You can't format C drive while you are in windows.
It must be done using your OS disk. You will need to change the boot sequence in bios.
To change
Boot Sequence in your
BIOSReboot the system and at the first post screen
(where it is counting up memory) start tapping the
DEL button
This will enter you into the
Bios\Cmos area.
Find the
Advanced area and click
Enter Look for
Boot Sequence or
Boot Options and highlight that click
EnterNow highlight the first drive and follow the directions on the bottom of the screen on how to modify it and change it to
CDrom.
Change the second drive to the
C or Main DriveOnce that is done then click
F10 to Save and Exit You will prompted to enter
Y to verify
Save and Exit. Click
Y and the system will now reboot with the new settings.
Go
Here for step by step instructions on how to partition, format, and install XP fresh