OK,
Download the Windows 95 boot disk from here
Bootdisk.Com then make it onto a floppy on a windows machine (its a self extracting exe). Then boot to the floppy disk in the computer you want to format. When you are presented with
at that prompt type
Then you will be presented with a list saying some options, select option 3...
Code:
3. Delete partition or logical DOS drive.
You will be presented with another list. Select option 4...
Code:
4. Delete a non-DOS partition.
Then select the Linux partition. This may be named in an odd manner or may be known as unknown, there may be more than one of them. Delete them all.
Then put in your operating system install disk, and perform your installation. Remember youll need to reset up any partitions that you deleted. For example if you still wanted to partitions you would need to create these. The Windows setup allows you to make FAT32 and NTFS filesystems so the full size of the disk, or to a specified amount. Linux installations also allow something similar.