diff --git a/src/base/path.cpp b/src/base/path.cpp
index 66270154c..51bea7694 100644
--- a/src/base/path.cpp
+++ b/src/base/path.cpp
@@ -59,6 +59,14 @@ namespace
         });
         return hasSeparator ? QDir::cleanPath(path) : path;
     }
+
+#ifdef Q_OS_WIN
+    bool hasDriveLetter(const QStringView path)
+    {
+        const QRegularExpression driveLetterRegex {u"^[A-Za-z]:/"_qs};
+        return driveLetterRegex.match(path).hasMatch();
+    }
+#endif
 }
 
 Path::Path(const QString &pathStr)
@@ -73,15 +81,24 @@ Path::Path(const std::string &pathStr)
 
 bool Path::isValid() const
 {
+    // does not support UNC path
+
     if (isEmpty())
         return false;
 
+    // https://stackoverflow.com/a/31976060
 #if defined(Q_OS_WIN)
-    const QRegularExpression regex {u"[:?\"*<>|]"_qs};
+    QStringView view = m_pathStr;
+    if (hasDriveLetter(view))
+        view = view.mid(3);
+
+    // \\37 is using base-8 number system
+    const QRegularExpression regex {u"[\\0-\\37:?\"*<>|]"_qs};
+    return !regex.match(view).hasMatch();
 #elif defined(Q_OS_MACOS)
     const QRegularExpression regex {u"[\\0:]"_qs};
 #else
-    const QRegularExpression regex {u"[\\0]"_qs};
+    const QRegularExpression regex {u"\\0"_qs};
 #endif
     return !m_pathStr.contains(regex);
 }
@@ -93,11 +110,17 @@ bool Path::isEmpty() const
 
 bool Path::isAbsolute() const
 {
+    // `QDir::isAbsolutePath` treats `:` as a path to QResource, so handle it manually
+    if (m_pathStr.startsWith(u':'))
+        return false;
     return QDir::isAbsolutePath(m_pathStr);
 }
 
 bool Path::isRelative() const
 {
+    // `QDir::isRelativePath` treats `:` as a path to QResource, so handle it manually
+    if (m_pathStr.startsWith(u':'))
+        return true;
     return QDir::isRelativePath(m_pathStr);
 }
 
@@ -108,6 +131,8 @@ bool Path::exists() const
 
 Path Path::rootItem() const
 {
+    // does not support UNC path
+
     const int slashIndex = m_pathStr.indexOf(u'/');
     if (slashIndex < 0)
         return *this;
@@ -125,6 +150,8 @@ Path Path::rootItem() const
 
 Path Path::parentPath() const
 {
+    // does not support UNC path
+
     const int slashIndex = m_pathStr.lastIndexOf(u'/');
     if (slashIndex == -1)
         return {};
@@ -135,8 +162,8 @@ Path Path::parentPath() const
 #ifdef Q_OS_WIN
     // should be `c:/` instead of `c:`
     // Windows "drive letter" is limited to one alphabet
-    if ((slashIndex == 2) && (m_pathStr.at(1) == u':'))
-        return createUnchecked(m_pathStr.left(slashIndex + 1));
+    if ((slashIndex == 2) && hasDriveLetter(m_pathStr))
+        return (m_pathStr.size() == 3) ? Path() : createUnchecked(m_pathStr.left(slashIndex + 1));
 #endif
     return createUnchecked(m_pathStr.left(slashIndex));
 }
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 266e42040..ad00a4bdc 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -12,6 +12,7 @@ include_directories("../src")
 set(testFiles
     testalgorithm.cpp
     testorderedset.cpp
+    testpath.cpp
     testutilscompare.cpp
     testutilsgzip.cpp
     testutilsstring.cpp
diff --git a/test/testpath.cpp b/test/testpath.cpp
new file mode 100644
index 000000000..7dd7f3b6e
--- /dev/null
+++ b/test/testpath.cpp
@@ -0,0 +1,293 @@
+/*
+ * Bittorrent Client using Qt and libtorrent.
+ * Copyright (C) 2022  Mike Tzou (Chocobo1)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ * In addition, as a special exception, the copyright holders give permission to
+ * link this program with the OpenSSL project's "OpenSSL" library (or with
+ * modified versions of it that use the same license as the "OpenSSL" library),
+ * and distribute the linked executables. You must obey the GNU General Public
+ * License in all respects for all of the code used other than "OpenSSL".  If you
+ * modify file(s), you may extend this exception to your version of the file(s),
+ * but you are not obligated to do so. If you do not wish to do so, delete this
+ * exception statement from your version.
+ */
+
+#include <QtGlobal>
+#include <QTest>
+
+#include "base/global.h"
+#include "base/path.h"
+
+class TestPath final : public QObject
+{
+    Q_OBJECT
+    Q_DISABLE_COPY_MOVE(TestPath)
+
+public:
+    TestPath() = default;
+
+private slots:
+    void testConstructors() const
+    {
+        QVERIFY(Path(u""_qs) == Path(std::string("")));
+        QVERIFY(Path(u"abc"_qs) == Path(std::string("abc")));
+        QVERIFY(Path(u"/abc"_qs) == Path(std::string("/abc")));
+        QVERIFY(Path(uR"(\abc)"_qs) == Path(std::string(R"(\abc)")));
+
+#ifdef Q_OS_WIN
+        QVERIFY(Path(uR"(c:)"_qs) == Path(std::string(R"(c:)")));
+        QVERIFY(Path(uR"(c:/)"_qs) == Path(std::string(R"(c:/)")));
+        QVERIFY(Path(uR"(c:/)"_qs) == Path(std::string(R"(c:\)")));
+        QVERIFY(Path(uR"(c:\)"_qs) == Path(std::string(R"(c:/)")));
+        QVERIFY(Path(uR"(c:\)"_qs) == Path(std::string(R"(c:\)")));
+
+        QVERIFY(Path(uR"(\\?\C:)"_qs) == Path(std::string(R"(\\?\C:)")));
+        QVERIFY(Path(uR"(\\?\C:/)"_qs) == Path(std::string(R"(\\?\C:/)")));
+        QVERIFY(Path(uR"(\\?\C:/)"_qs) == Path(std::string(R"(\\?\C:\)")));
+        QVERIFY(Path(uR"(\\?\C:\)"_qs) == Path(std::string(R"(\\?\C:/)")));
+        QVERIFY(Path(uR"(\\?\C:\)"_qs) == Path(std::string(R"(\\?\C:\)")));
+
+        QVERIFY(Path(uR"(\\?\C:\abc)"_qs) == Path(std::string(R"(\\?\C:\abc)")));
+#endif
+    }
+
+    void testIsValid() const
+    {
+        QCOMPARE(Path().isValid(), false);
+        QCOMPARE(Path(u""_qs).isValid(), false);
+
+        QCOMPARE(Path(u"/"_qs).isValid(), true);
+        QCOMPARE(Path(uR"(\)"_qs).isValid(), true);
+
+        QCOMPARE(Path(u"a"_qs).isValid(), true);
+        QCOMPARE(Path(u"/a"_qs).isValid(), true);
+        QCOMPARE(Path(uR"(\a)"_qs).isValid(), true);
+
+        QCOMPARE(Path(u"a/b"_qs).isValid(), true);
+        QCOMPARE(Path(uR"(a\b)"_qs).isValid(), true);
+        QCOMPARE(Path(u"/a/b"_qs).isValid(), true);
+        QCOMPARE(Path(uR"(/a\b)"_qs).isValid(), true);
+        QCOMPARE(Path(uR"(\a/b)"_qs).isValid(), true);
+        QCOMPARE(Path(uR"(\a\b)"_qs).isValid(), true);
+
+        QCOMPARE(Path(u"//"_qs).isValid(), true);
+        QCOMPARE(Path(uR"(\\)"_qs).isValid(), true);
+        QCOMPARE(Path(u"//a"_qs).isValid(), true);
+        QCOMPARE(Path(uR"(\\a)"_qs).isValid(), true);
+
+#if defined Q_OS_MACOS
+        QCOMPARE(Path(u"\0"_qs).isValid(), false);
+        QCOMPARE(Path(u":"_qs).isValid(), false);
+#elif defined Q_OS_WIN
+        QCOMPARE(Path(u"c:"_qs).isValid(), false);
+        QCOMPARE(Path(u"c:/"_qs).isValid(), true);
+        QCOMPARE(Path(uR"(c:\)"_qs).isValid(), true);
+        QCOMPARE(Path(uR"(c:\a)"_qs).isValid(), true);
+        QCOMPARE(Path(uR"(c:\a\b)"_qs).isValid(), true);
+
+        for (int i = 0; i <= 31; ++i)
+            QCOMPARE(Path(QChar(i)).isValid(), false);
+        QCOMPARE(Path(u":"_qs).isValid(), false);
+        QCOMPARE(Path(u"?"_qs).isValid(), false);
+        QCOMPARE(Path(u"\""_qs).isValid(), false);
+        QCOMPARE(Path(u"*"_qs).isValid(), false);
+        QCOMPARE(Path(u"<"_qs).isValid(), false);
+        QCOMPARE(Path(u">"_qs).isValid(), false);
+        QCOMPARE(Path(u"|"_qs).isValid(), false);
+#else
+        QCOMPARE(Path(u"\0"_qs).isValid(), false);
+#endif
+    }
+
+    void testIsEmpty() const
+    {
+        QCOMPARE(Path().isEmpty(), true);
+        QCOMPARE(Path(u""_qs).isEmpty(), true);
+
+        QCOMPARE(Path(u"\0"_qs).isEmpty(), false);
+
+        QCOMPARE(Path(u"/"_qs).isEmpty(), false);
+        QCOMPARE(Path(uR"(\)"_qs).isEmpty(), false);
+
+        QCOMPARE(Path(u"a"_qs).isEmpty(), false);
+        QCOMPARE(Path(u"/a"_qs).isEmpty(), false);
+        QCOMPARE(Path(uR"(\a)"_qs).isEmpty(), false);
+
+        QCOMPARE(Path(uR"(c:)"_qs).isEmpty(), false);
+        QCOMPARE(Path(uR"(c:/)"_qs).isEmpty(), false);
+        QCOMPARE(Path(uR"(c:\)"_qs).isEmpty(), false);
+    }
+
+    void testIsAbsolute() const
+    {
+        QCOMPARE(Path().isAbsolute(), false);
+        QCOMPARE(Path(u""_qs).isAbsolute(), false);
+
+#ifdef Q_OS_WIN
+        QCOMPARE(Path(u"/"_qs).isAbsolute(), true);
+        QCOMPARE(Path(uR"(\)"_qs).isAbsolute(), true);
+
+        QCOMPARE(Path(u"a"_qs).isAbsolute(), false);
+        QCOMPARE(Path(u"/a"_qs).isAbsolute(), true);
+        QCOMPARE(Path(uR"(\a)"_qs).isAbsolute(), true);
+
+        QCOMPARE(Path(u"//"_qs).isAbsolute(), true);
+        QCOMPARE(Path(uR"(\\)"_qs).isAbsolute(), true);
+        QCOMPARE(Path(u"//a"_qs).isAbsolute(), true);
+        QCOMPARE(Path(uR"(\\a)"_qs).isAbsolute(), true);
+
+        QCOMPARE(Path(uR"(c:)"_qs).isAbsolute(), true);
+        QCOMPARE(Path(uR"(c:/)"_qs).isAbsolute(), true);
+        QCOMPARE(Path(uR"(c:\)"_qs).isAbsolute(), true);
+        QCOMPARE(Path(uR"(c:\a)"_qs).isAbsolute(), true);
+        QCOMPARE(Path(uR"(c:\a\b)"_qs).isAbsolute(), true);
+
+        QCOMPARE(Path(uR"(\\?\C:)"_qs).isAbsolute(), true);
+        QCOMPARE(Path(uR"(\\?\C:/)"_qs).isAbsolute(), true);
+        QCOMPARE(Path(uR"(\\?\C:\)"_qs).isAbsolute(), true);
+        QCOMPARE(Path(uR"(\\?\C:\a)"_qs).isAbsolute(), true);
+        QCOMPARE(Path(uR"(\\?\C:\a\b)"_qs).isAbsolute(), true);
+#else
+        QCOMPARE(Path(u"/"_qs).isAbsolute(), true);
+        QCOMPARE(Path(uR"(\)"_qs).isAbsolute(), false);
+
+        QCOMPARE(Path(u"a"_qs).isAbsolute(), false);
+        QCOMPARE(Path(u"/a"_qs).isAbsolute(), true);
+        QCOMPARE(Path(uR"(\a)"_qs).isAbsolute(), false);
+
+        QCOMPARE(Path(u"//"_qs).isAbsolute(), true);
+        QCOMPARE(Path(uR"(\\)"_qs).isAbsolute(), false);
+        QCOMPARE(Path(u"//a"_qs).isAbsolute(), true);
+        QCOMPARE(Path(uR"(\\a)"_qs).isAbsolute(), false);
+#endif
+    }
+
+    void testIsRelative() const
+    {
+        QCOMPARE(Path().isRelative(), true);
+        QCOMPARE(Path(u""_qs).isRelative(), true);
+
+#if defined Q_OS_WIN
+        QCOMPARE(Path(u"/"_qs).isRelative(), false);
+        QCOMPARE(Path(uR"(\)"_qs).isRelative(), false);
+
+        QCOMPARE(Path(u"a"_qs).isRelative(), true);
+        QCOMPARE(Path(u"/a"_qs).isRelative(), false);
+        QCOMPARE(Path(uR"(\a)"_qs).isRelative(), false);
+
+        QCOMPARE(Path(u"//"_qs).isRelative(), false);
+        QCOMPARE(Path(uR"(\\)"_qs).isRelative(), false);
+        QCOMPARE(Path(u"//a"_qs).isRelative(), false);
+        QCOMPARE(Path(uR"(\\a)"_qs).isRelative(), false);
+
+        QCOMPARE(Path(uR"(c:)"_qs).isRelative(), false);
+        QCOMPARE(Path(uR"(c:/)"_qs).isRelative(), false);
+        QCOMPARE(Path(uR"(c:\)"_qs).isRelative(), false);
+        QCOMPARE(Path(uR"(c:\a)"_qs).isRelative(), false);
+        QCOMPARE(Path(uR"(c:\a\b)"_qs).isRelative(), false);
+
+        QCOMPARE(Path(uR"(\\?\C:)"_qs).isRelative(), false);
+        QCOMPARE(Path(uR"(\\?\C:/)"_qs).isRelative(), false);
+        QCOMPARE(Path(uR"(\\?\C:\)"_qs).isRelative(), false);
+        QCOMPARE(Path(uR"(\\?\C:\a)"_qs).isRelative(), false);
+        QCOMPARE(Path(uR"(\\?\C:\a\b)"_qs).isRelative(), false);
+#else
+        QCOMPARE(Path(u"/"_qs).isRelative(), false);
+        QCOMPARE(Path(uR"(\)"_qs).isRelative(), true);
+
+        QCOMPARE(Path(u"a"_qs).isRelative(), true);
+        QCOMPARE(Path(u"/a"_qs).isRelative(), false);
+        QCOMPARE(Path(uR"(\a)"_qs).isRelative(), true);
+
+        QCOMPARE(Path(u"//"_qs).isRelative(), false);
+        QCOMPARE(Path(uR"(\\)"_qs).isRelative(), true);
+        QCOMPARE(Path(u"//a"_qs).isRelative(), false);
+        QCOMPARE(Path(uR"(\\a)"_qs).isRelative(), true);
+#endif
+    }
+
+    void testRootItem() const
+    {
+        QCOMPARE(Path().rootItem(), Path());
+        QCOMPARE(Path(u""_qs).rootItem(), Path());
+
+        QCOMPARE(Path(u"/"_qs).rootItem(), Path(u"/"_qs));
+        QCOMPARE(Path(uR"(\)"_qs).rootItem(), Path(uR"(\)"_qs));
+
+        QCOMPARE(Path(u"a"_qs).rootItem(), Path(u"a"_qs));
+        QCOMPARE(Path(u"/a"_qs).rootItem(), Path(u"/"_qs));
+        QCOMPARE(Path(u"/a/b"_qs).rootItem(), Path(u"/"_qs));
+
+        QCOMPARE(Path(u"//"_qs).rootItem(), Path(u"/"_qs));
+        QCOMPARE(Path(uR"(\\)"_qs).rootItem(), Path(uR"(\\)"_qs));
+        QCOMPARE(Path(u"//a"_qs).rootItem(), Path(u"/"_qs));
+
+#ifdef Q_OS_WIN
+        QCOMPARE(Path(uR"(\a)"_qs).rootItem(), Path(uR"(\)"_qs));
+        QCOMPARE(Path(uR"(\\a)"_qs).rootItem(), Path(uR"(\)"_qs));
+
+        QCOMPARE(Path(uR"(c:)"_qs).rootItem(), Path(uR"(c:)"_qs));
+        QCOMPARE(Path(uR"(c:/)"_qs).rootItem(), Path(uR"(c:/)"_qs));
+        QCOMPARE(Path(uR"(c:\)"_qs).rootItem(), Path(uR"(c:\)"_qs));
+        QCOMPARE(Path(uR"(c:\)"_qs).rootItem(), Path(uR"(c:/)"_qs));
+        QCOMPARE(Path(uR"(c:\a)"_qs).rootItem(), Path(uR"(c:\)"_qs));
+        QCOMPARE(Path(uR"(c:\a\b)"_qs).rootItem(), Path(uR"(c:\)"_qs));
+#else
+        QCOMPARE(Path(uR"(\a)"_qs).rootItem(), Path(uR"(\a)"_qs));
+        QCOMPARE(Path(uR"(\\a)"_qs).rootItem(), Path(uR"(\\a)"_qs));
+#endif
+    }
+
+    void testParentPath() const
+    {
+        QCOMPARE(Path().parentPath(), Path());
+        QCOMPARE(Path(u""_qs).parentPath(), Path());
+
+        QCOMPARE(Path(u"/"_qs).parentPath(), Path());
+        QCOMPARE(Path(uR"(\)"_qs).parentPath(), Path());
+
+        QCOMPARE(Path(u"a"_qs).parentPath(), Path());
+        QCOMPARE(Path(u"/a"_qs).parentPath(), Path(u"/"_qs));
+
+        QCOMPARE(Path(u"//"_qs).parentPath(), Path());
+        QCOMPARE(Path(uR"(\\)"_qs).parentPath(), Path());
+        QCOMPARE(Path(u"//a"_qs).parentPath(), Path(u"/"_qs));
+
+        QCOMPARE(Path(u"a/b"_qs).parentPath(), Path(u"a"_qs));
+
+#ifdef Q_OS_WIN
+        QCOMPARE(Path(uR"(\a)"_qs).parentPath(), Path(uR"(\)"_qs));
+        QCOMPARE(Path(uR"(\\a)"_qs).parentPath(), Path(uR"(\)"_qs));
+        QCOMPARE(Path(uR"(a\b)"_qs).parentPath(), Path(u"a"_qs));
+
+        QCOMPARE(Path(uR"(c:)"_qs).parentPath(), Path());
+        QCOMPARE(Path(uR"(c:/)"_qs).parentPath(), Path());
+        QCOMPARE(Path(uR"(c:\)"_qs).parentPath(), Path());
+        QCOMPARE(Path(uR"(c:\a)"_qs).parentPath(), Path(uR"(c:\)"_qs));
+        QCOMPARE(Path(uR"(c:\a\b)"_qs).parentPath(), Path(uR"(c:\a)"_qs));
+#else
+        QCOMPARE(Path(uR"(\a)"_qs).parentPath(), Path());
+        QCOMPARE(Path(uR"(\\a)"_qs).parentPath(), Path());
+        QCOMPARE(Path(uR"(a\b)"_qs).parentPath(), Path());
+#endif
+    }
+
+    // TODO: add tests for remaining methods
+};
+
+QTEST_APPLESS_MAIN(TestPath)
+#include "testpath.moc"