Does the type of Windows 7 affect compatibility? I still use XP but was looking into upgrading to 7. The Microsoft site lists Windows7 "Home edition" and "Professional" where the latter has XP compatibility.

Do games run better "Professional" than on "Home Edition".

Does not matter at all. The "XP Mode" of Windows 7 Professional Edition is actually a virtual machine, which is quite useless to most users. Which edition of Windows 7 you run does not affect compatibility with GOG games in any way.

Basically, if you do not know or understand what benefits the Professional Edition would give you, you most likely don't need it. Stick with Home and you will be fine.

Is there some way to help GOG to (hack?) games to make them work on Windows Vista-7?... I really don't know how they do that..

And you call yourself a virus...

My laptop is on Win 7 64-bit, i have same problem....

This is the current (2013-03-02) list of all games not officially stated working on Windows 7:

• Arx Fatalis – works, confirmed by GameRager
• Blood 2: The Chosen + Expansion – works, confirmed by GameRager
• Disciples: Sacred Lands Gold
• Evolva
• Freespace 2 – works on 32bit (confirmed by duxcorvan) and 64bit (confirmed by ZivilSword)
• Gorky 17 – works with ATI/AMD graphics card, confirmed by timppu
• Gothic
• The Incredible Machine Mega Pack
• Independence War 2: Edge of Chaos
• Interstate 76
• The Longest Journey – works, confirmed by SLP2000
• The Manhole: Masterpiece Edition
• MDK 2 – there is a level loading bug: http://www.gog.com/forum/mdk_series/will_mdk_ii_work_on_a_windows_7_machine
• Messiah – works, confirmed by GameRager
• Real Myst – works, confirmed by roflplatypus
• Red Baron Pack
• Sanitarium – works, confirmed by GameRager
• Sensible Soccer 2006
• Silent Hunter II – works with disc version, confirmed by tinyE
• UFO: Aftermath

Maybe someone who owns one of these can confirm or disprove it.

Fixed. There's a slight-but-very-important difference.

I can confirm the ones listed above work fine on Win7-64bit(As I have started/played parts of the games above on Win7-64bit).

Curse you, logic! That’s what’s happening when you try to come up with complex sentences in a foreign language. :-) I understand English very well but have few practice in writing or even speaking. I will correct my posting, thanks for the hint.

Freespace 2 works well in my Win 8 (which is mostly a reskinned and tuned Win 7). I admit is the 32 bit campy version, guess there may be trouble in 64 bit.

Quite often the problem is somewhere else (e.g. drivers, HW features etc.) than the OS itself.

For example, I've played Gorky17 through in Windows 7/64bit (on a Lenovo ThinkPad T400 laptop), but I think NVidia users may have more issues with it than ATI/AMD users, at least if they want to run it 3D accelerated.

I don't know if NVidia users had less problems in WinXP with this game, I don't have a WinXP machine with NVidia GPU (only ATI).

I've been considering buying silent hunter 2, for my tiny win7 laptop. But it's quite expensive, for a game that seems to have issues with win7.

Does anyone have details on this ?

I may try my German CD version from around 2004. If this works, the GOG version should do, too.

Hm, quite old games for Windows can be problematic in graphics, but why should there be a difference between NVidia and ATI/AMD? Unless it’s a Voodoo special edition, I don’t see the point.
I had more problems with Windows7 itself, e.g. playing Starcraft. This is quite impossible playing fullscreen without colouring issues, unless you use Windows XP. And this is not the only game with this special problem. Only patching could help, and I think, GOG has access to the source code, if it helps.

Sorry I'm late on this. I have SH 1 & 2 on disc and the only problems I've had with them is that I don't like them. :D
That not withstanding, on my desktop with Win7 they run perfectly.