Boot to Win98SE startup disk (It is the best OS made boot disk ever). Type in debug at the A: prompt.
Enter in the following commands:
Blue: what you type in.
Pink: what is displayed on the screen. (DO NOT TYPE THIS IN!)
Black: this is useful information. (DO NOT TYPE THIS IN!)
================================================== ===================
To delete partitions on a hard drive:
-------------------------------------------
-F 220 L1000 0 (ENTER)
-A CS: 100 (ENTER)
xxxx:0100 MOV AX,301 (ENTER)
xxxx:0103 MOV BX,200 (ENTER)
xxxx:0106 MOV CX,1 (ENTER)
xxxx:0109 MOV DX,80 (ENTER) <---"80" for hd1, "81" for hd2 >
xxxx:010C INT 13 (ENTER)
xxxx:010E INT 20 (ENTER)
xxxx:0110 (ENTER) <-------BLANK LINE "VERY IMPORTANT" >
-G (ENTER)
Program terminated normally
- (CTRL)-(ALT)-(DEL) to reboot system
THEN... install XP
http://www.fdisk.com/fdisk/HardDrive.htm