|"so as i said i'm letting sleeping dogs lie"|
More info is needed if you want to try.
"due to an unknown fault..."can't remember the rest"
The EXACT message can be found in Event viewer, if it will let you.
HOW TO: View and Manage Event Logs in Event Viewer in Windows XP
Start > Run, Copy & Paste > eventvwr.msc /s & press Enter.
"which given my typing skills will undoubtedly contain errors"
To avoid typo's, always Copy & Paste.
"after which i can format the hard drive and start again"
If you do decide to reinstall, make sure when you reinstall, you delete ALL partitions & format to NTFS.
XP - D to Delete the selected partition
Here are some examples of why you delete all partitions.