I AM TRYING TO REPLACE SEGATE BARRACUDA 7200.7

If your u8 has an operating system installed, yes, you can do that.
Be sure to boot the u8 in Safe Mode to copy your files.

I would also recommend checking the copied files for viruses before you use them.

with a virus on the hard drive you don't because then you'll get a virus on your new hard drive, and typing in caps is just annoying

I suggest you to create a bootable usb pendrive with win98se OS, there are some utilities like NTFSDOS.EXE, NTFSREAD.EXE etc that allow you to access NTFS file system in windows 98, you can copy antivirus files of Quick Heal (emgscan.exe), Norton 2003(navdx.exe) trial versions with latest updates along with the supporting files in this pen drive, use this pendrive as your boot device, once booted from the pendrive you can remove the viruses easily. I use the same technique and have solved 1000's of such problems, I use a 256 MB Transcend USB Pen drive, the drivers for transcend allows you to easily create a bootable pen drive