diff --git a/CHANGELOG b/CHANGELOG
index 4a80948..b364639 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -28,3 +28,7 @@ Version 0.6, released July 8 2011:
 	- Fix calculation of difficulty for multiple prefixes
 	- When prefixes overlap, output the discarded prefix as 
 	  well as the existing prefix with which it overlaps
+
+Version 0.7, released July 8 2011:
+	- Use GetLogicalProcessorInformation() to count CPUs on Windows,
+	  because GetActiveProcessorCount() is Windows 7 and newer.
diff --git a/vanitygen.c b/vanitygen.c
index 2c805cc..b55e335 100644
--- a/vanitygen.c
+++ b/vanitygen.c
@@ -1969,6 +1969,7 @@ read_file(FILE *fp, char ***result, int *rescount)
 	return ret;
 }
 
+#if !defined(_WIN32)
 int
 count_processors(void)
 {
@@ -1976,10 +1977,6 @@ count_processors(void)
 	char buf[512];
 	int count = 0;
 
-#if defined(_WIN32)
-	return GetActiveProcessorCount(ALL_PROCESSOR_GROUPS);
-#endif
-
 	fp = fopen("/proc/cpuinfo", "r");
 	if (!fp)
 		return -1;
@@ -1991,6 +1988,7 @@ count_processors(void)
 	fclose(fp);
 	return count;
 }
+#endif
 
 int
 start_threads(void *(*func)(void *), void *arg, int nthreads)
diff --git a/winglue.c b/winglue.c
index 0239bdf..c125914 100644
--- a/winglue.c
+++ b/winglue.c
@@ -5,6 +5,56 @@
 #define INLINE
 #define snprintf _snprintf
 
+
+int
+count_processors(void)
+{
+	typedef BOOL (WINAPI *LPFN_GLPI)(
+		PSYSTEM_LOGICAL_PROCESSOR_INFORMATION, PDWORD);
+	LPFN_GLPI glpi;
+	PSYSTEM_LOGICAL_PROCESSOR_INFORMATION buffer = NULL, ptr;
+	DWORD size = 0, count = 0, pos = 0, i, ret;
+
+	glpi = (LPFN_GLPI) GetProcAddress(GetModuleHandle(TEXT("kernel32")),
+					  "GetLogicalProcessorInformation");
+	if (!glpi)
+		return -1;
+
+	while (1) {
+		ret = glpi(buffer, &size);
+		if (ret)
+			break;
+		if (buffer)
+			free(buffer);
+		if (GetLastError() != ERROR_INSUFFICIENT_BUFFER)
+			return -1;
+		buffer = (PSYSTEM_LOGICAL_PROCESSOR_INFORMATION) malloc(size);
+		if (!buffer)
+			return -1;
+	}
+
+	for (ptr = buffer;
+	     (pos + sizeof(*ptr)) <= size;
+	     ptr++, pos += sizeof(*ptr)) {
+		switch (ptr->Relationship) {
+		case RelationProcessorCore:
+			for (i = ptr->ProcessorMask; i != 0; i >>= 1) {
+				if (i & 1)
+					count++;
+			}
+			count++;
+			break;
+		default:
+			break;
+		}
+	}
+
+	if (buffer)
+		free(buffer);
+	return count;
+}
+
+
 /*
  * struct timeval compatibility for Win32
  */