Windows 7 - Dropping Wireless Connection

Hi, I recently built a new PC and after I installed windows 7, I installed my wireless network adapter and that's when I started having issues. My internet connection will connect and be fully functional (I can surf the internet, chat online, etc.) for about 2-5 minutes until I lose connectivity. Afterwords, the wireless icon says there is still full connectivity, but I cannot use anything that requires internet. then after about 30 minutes it sometimes changes to "Limited Connectivity." Anyways in order to regain internet access I have to reboot and as soon as I reboot, I get internet access for 2-5 minutes until the whole problem starts again.

Wireless Adapter: Dynex Enhanced Wireless G USB Adapter
Operating System: Windows 7 64-bit Release Candidate

Any help would be greatly appreciated.

PS. I'm switching to Vista to see if its the Adapter that's the problem or Windows 7

Please Go Control Panel -> Power Option and check the setting.

I already unchecked the box that said "Allow windows to shut off this device to save power" before. Thanks for the suggestion though.

Anyone else have suggestions?