All you need to do is this:: Make back-ups of all your data first then >>
1. Boot the PC into MS DOS Mode
2. At the C:/format C:/ hit return (note the space between the T of format and C)
3. Type Y for yes to proceed
Once its formated insert the Floppy or set your BIOS to 1st boot from CD Rom have the windows CD in your rom and it will start to install..
If you use the Boot Floppy use CD Rom support then once its finished type in at the A:/ or C:/ prompt your CD drive letter per say D:/ hit return. Now if it is D:/(type) setup.. You should be ok from this point forward..