Anyway, as you probably know, you can't run Windows 3.00 in 386 Enhanced mode in Virtual PC. Attempting to do so will only result in Windows hanging at a black screen. The cause for this is Virtual PC's VGA BIOS, which uses the address space all the way up to CBFF, whereas VGA cards normally used A000-C7FF. This conflicts with Windows 386 memory management, which in turn hangs the system.
Luckily, Microsoft was aware of the issue back then and made a KB article with a fix for this. All you have to do to fix this issue is to open SYSTEM.INI of Windows 3.0 and find the [386Enh] section. Then just add the following line to that section: EMMExclude=A000-CBFF. Save the file and start Windows in 386 enhanced mode (win /e). The result should be the following:

This is best done under MS-DOS with EDIT, as MS-DOS has to be installed anyway + you don't have to reboot after modding. An alternative solution is to replace VPC's default Video BIOS (a generic Trio 32/64), with a different S3 BIOS, such as Trio3D2X (I can confirm this one doesn't conflict with Windows 3.00).