Partition Magic seems to be able to do that.

Thankyou for your indepth reply, I don't even know what 'partition magic' is????

What is 'partition magic' ????

Click here.

To convert a volume to NTFS from the command prompt
1.
Open Command Prompt. Click Start, point to All Programs, point to Accessories, and then click Command Prompt.
2.
In the command prompt window, type: convert drive_letter: /fs:ntfs
For example, typing convert D: /fs:ntfs would format drive D: with the ntfs format. You can convert FAT or FAT32 volumes to NTFS with this command.
Important Once you convert a drive or partition to NTFS, you cannot simply convert it back to FAT or FAT32. You will need to reformat the drive or partition which will erase all data, including programs and personal files, on the partition.

Thankyou Kaosreigns the conversion seems straightforward, but this is an OEM PC, no installation disc, what happens to the installation (hidden files) on the hard drive, ie if the PC needs to be reset to factory standards again, will the files still be avaliable to enable this, will they be lost in the conversion, stay as FAT or also be converted to NTFS? The lady in question would like the PC to remain NTFS so converting back to FAT is not a problem.

Nothing, usually. Are the restoration files stored on a separate partition on the drive?

Thankyou DMR, the files are on the same hard drive, but unless the drive creates its own partition (unlikely) after installation of OEM files, no partition. Still would like some feedback of just deleting the hard drive, re-installing with an XP Home disc, but instead of using product key of the disc use the OEM product key, would that work ?
thanx Eamon

In theory, yes- that should work. However, I can't give you a 100% guarantee on that; "real life" doesn't always subscribe to theory, and OEM setups can have their own peculiarities.

It sounds like you're overcomplicating/overthinking this a bit. If you have an XP Home disc, why are you worried about hanging on to the option of the OEM's factory restore? Conversely, why think about reformatting with an XP install CD if you have the factory restore option? If the system gets hosed badly enough that you have to use either option, you're looking at a reformat of the drive and a full reinstall of the OS and all of your applications. The FAT vs NTFS issue becomes pretty moot at that point.

If the Time company you refer to is the UK-based computer company, they are still in operation as far as I know. You can find customer support numbers on the following site; why not ask them directly?:
http://www.totalcaresupport.com/