Take the following steps:
1. Obtain a boot diskette
--
http://www.bootdisk.com2. Insert boot diskette
3. Enter BIOS
4. Set first boot device to A:
5. Insert CD-ROM
6. Save and exit the BIOS
7. Choose to boot with CD-ROM support once prompted.
From here you have several choices:
I. You can create new partitions typing Fdisk in A:\
II. You can format by typing format C:\ in A:\
-- I advise to do both before installing Windows.
8. Once done type X:\
9. Type Setup in X:\ prompt
-- Where X is the drive letter of your CD-ROM. Often D:\