Finally something I can help with! Okay, I take it you want these systems back to Windows? Well you're going to need a working system to do this on of course, but you also need a Windows XP disc with SP1 or newer slipstreamed in. Once you've achieved that, you need some software called UBCD4Win which is available here
UBCD for Windows and the software to make USB booting possible
http://www.ezpcfix.net/ubcd4win/UBUSB.exe
Once you've got UBCD4Win you need to point it at files of your XP disc(they don't need to be on an actual disc, but you do need all of the files). It'll then ask you to copy them onto a hard drive if they're not already, okay, once you're this far, press build on the UBCD4Win interface. Building will take a while, but once done it's time to get USB booting. Open UBUSB with your flash dongle already in and detected, it should pick up your dongle for you. Be sure to tick Quick Format, untick "Create CD Image for USB...". The programs need to know where the BartPE folder from UBCDWin is, so under BartPE Folder, press the three dots to browse, and set it correctly normally C:\UBCD4Win\BartPE\.
Once you've set all those options, press GO. Once done you can press test USB on the system you're on to see if USB booting is working, if it is, you can go ahead and set USB booting in the BIOS on the machine you need to and give it a whirl, if it doesn't work, try using one of the other bootloaders and starting the USB booting process again.
Once you're booting and have got UBCD4Win up and going, you can go ahead and format your hard drives should you choose. But if you look under the various menus, there's a windows XP installer, which will start an installation if windows XP going on one of your hard drives, so if you can find a way to get the windows XP files onto the PC(not the USB booting files you've made), then you can start the install going and be on your way to a working system.
Good luck!