Error Message, Starting ANY games

I've just recently upgraded to Vista from XP. Had everything installed and
working great for about 4 days now. Even managed to installed most of my
older games and softwares.
About 6 hours ago, none of my games will start from the "GAME" folder. I
get an error message that saids "This file does not have a program associated
with it for performing this action. Create an association in the Set
Associations control panel."
I tried to do what it said, and went to the Association Control Panel and
looked for all the pre-installed Windows games. I've found all of them, but
they all seem to be a link to start in the Media Center, because the file
association has a "-MS" on the end of them. So i didn't make any changes to
those files, or the association.
Tracked down where the "Game Folder" keeps it links to see if the links were
physically screwed up. (One word of suggestion as a later update. You guys
should put a Right-click menu locater for the links in the "Games Folder"
icons.) I've located all the Windows games (here:
C:\Users\NAME\AppData\Local\Microsoft\Windows\Game Explorer\
{AF698A5B-24D6-4f78-AE95-204B09EDC7B6}\PlayTasks\0\Mahjong Titan, and all the
other games in the "{***}" folders) I double-click on the links here, and
the games open up. This work for all other games as well. It also works
from the "Start Menu" as well. So, i know the link is fine.
As a last resort, I went to Control Panel > Programs > Turn Windows features
on or off and deselected the game an have it all removed. Once that was
completed, I turned it back on, and had all the games reinstalled again.
Rebooted the machine, and i still get the error message.
As stated before, none of the games will work from the "Games Folder". Not
even the ones i installed, like Half-Life 2, Freelancer, etc. All these
games work from the "Start Menu", but what's the point in having a "Games
Folder" if it doesn't work. And again, i've only had Vista for 4-5 days now,
and i'm still figuring the in's and out's.

So, can anyone Please help me with this problem????

**One last thing. I don't know if this will help, but i think it's worth
mentioning. I have System Mechanic 7.1.7 installed on my machine. I know
this could in some way effect the Registry, but i'm 90% sure this didn't have
anything to do with it. I know this because, i UNDID any modifications i
made thru System Mechanic when the problem arose, and it didn't fix anything.