If I havemy USB connectedCanon multifunction printer plugged into my front USB ports it will not allow Windows 7 RC to boot up. Also, even though I am running 3 gigs of RAM, My keyboard will notrespond properly while Windows is performing some other intensive task. I find these problems to be a bit hectic at times. Any help would be greatly appreciated.

Not long ago I read another user talking about not beeing able to boot up while a usb device was plugged in a Asus M4A78-EM motherboad. The issue was fixed by updating the bios to latest version. Note that updating the bios is not a trivial process and can brick your motherboard. It is advised to see the exactly model in the website of the manufacturer and see if you are already running the last bios version. If not, follow carrefuly the recomendations of the manufacturer to do the update. About the keyboard, what exactly happens? And what hardware are you using?