Use F8 to select open in MS DOS only. I have no idea what prompt letter will come up. If it is C then you won't be able to F disk because you can't wipe out the disk where the DOS files are stored.
Maybe it creates an artifical A prompt. The system files [DOS files] should be on the hard drive but maybe it creates a RAM drive. Pure WAG on my part.
BTW didn't you get a recovery CD with the machine??? Most proprietary systems give that rather than the actual Operating System disk. The purpose of the recovery CD is to do what you want.
how can i wipe out my computer and reinstall windows me if i dont have an a drive to fdisk i have an e600 thinkpad