Windows 7: Bad Game Quality

Hey all!
I've installed and activated Windows 7 recently.
I'm very happy with it!
Got some awesome games on it, Bejeweled 3 for example, it's so much better than with Vista!
Anyway, there is also a game called Puzzle Quest, that I have, (for people who dont know what it it is, in short: alot more, look it up please (XD) but it's basically another gem-switching game)
I always loved the game!
But now I have installed Windows 7, with every move I make, it's all halting/hitchy (don't know a good word for it)
Let's jsut call it slow and irritating.
I already installed new drivers and that didn't solve the problem.
I've been working with resolutions, from the game and Windows itself, nothing helped.
What to do?

Are those games Flash-based? You could try updating your Adobe Flash Player.

no, it's not.
since it's a pc game you just gotta install... :/

Video card drivers updated and installed, or just using the default driver that Windows installed for it?

That most certainly doesn't mean it isn't a Flash-based game.

Try compatibility mode Windows XP service pack 2 or 3. Right click on icon and select properties, then select the compatibility tab.

@hybridfan

sorry, I really didn't get that :P
I mean, how can i use XP sp's with 7? :/

Updated and installed, dowloaded from the original Nvidia site

Tried running the game in compatibility mode?

Compatibility Mode

If not try it in XP compatibility and see if that fixes it.

Well, damn, now you made me recall "Machinarium". I gotta find this among my pile of backups and play it again

@DUSKvsDAWN, it would help a lot if you filled in your system specs (http://www.sevenforums.com/256049-post4.html)
I'm surprised nobody mentioned this already.