My apologies im terrible at these sort of things but i wouldnt know how to reinstall using a flash drive or how i would get my hards on an OS.
And by another unit do you mean another powersupply?
If you have a flash drive, you can d/load a Windows OS ISO file(whichever one you have) and install it on the drive using the tool in the link.
http://www.microsoftstore.com/store/msusa/html/pbPage.Help_Win7_usbdvd_dwnTool
And by another unit, I meant Psu.