I installed Ubuntu 8.04.3 on a usb drive instead of a CD
 

Now I Can't boot anything without the flash drive. I want to get windows to boot without the flash drive.

Hi,

I would suggest you grab the ubuntu Disc, boot it up into the live distribution and do a live reinstall of grub using grub-install specifying the drive you want it installed on... you might need to make a /boot partition... depending on how you have your PC configured.

If you need help on how to use grub-install then I can give it, but there are plenty of guides on how to do this that can be found on most search engines.