From experience, ANY graviteam game/patching on windows 7 leads to pain if installed to programs.
Agreed.
Some further information about this Windows 7 (and Vista) phenomenon:
The folders "C:\Program Files\", "C:\Program Files(x86)\" and "C:\Windows\" are protected locations.
Any changes to files in these folders may be 'virtualized', i.e. the updated version is
actually saved to a different location, under the user's profile folder.
To add to the confusion, evidently this does not happen all the time, or consistently.
So if you're lucky, you might get away with it once or twice, but somewhere down the line, the law of averages will start kicking in.