Adding to the list of Windows 7 issues: some games are creating duplicated entries in Games Explorer.
I am seeing it with Myst, Riven and Psychonauts, but I haven't installed all my GOG games in Win 7 yet.
At first I thought I was seeing, for some strange reason, links to my disc based versions of Myst and Riven, but I have removed every version in the computer. When I removed the GOG ones, both links were removed. When I later installed GOG's only, the problem appeared.
I don't have a disc release of Psychonauts, so the problem is linked to GOG's installer.
What's strange is that each icon shows different information, like version 220.127.116.11 or 18.104.22.168 for each Riven entry.
Could it be that the installer is creating both Win Vista and Win 7 game hooks?
OS: Windows 7 Home Premium x64
No, the "problem" is two things.
First, GOG's installer registers the game with Game Explorer using a GUID of their choosing (like any modern game labelled with "Games For Windows" does). The way to register in 7 works just as well in Vista (and has always been the official way, only Vista was more relaxed in what it accepted [not fully finalised, I believe] so GOG and others did it in a lazier way which is no longer accepted and produces the unusable icons under "Unspecified")
Second, Windows Vista's or 7's built-in "Legacy Games Detection" finds the game and sees that it is not registered in GE - because the GUID it expects is not present - so it registers the game with the GUID it does expect. Because it is a legacy game - created before there ever was a game explorer, much less have he installer use hooks for it - it surely can't be registered, right?
There may be more to it that just GUID matching, so something may get severely messed up if GOG just changed the GUIDs they use to whatever Windows expects for each game. I assume there is a pretty good reason they have not done so.