What does the law say about this situation...?

I set up a PC for a friend of my mom about a year ago to dual-boot 98/XP as she had a range of odd software that she needed to run. It was somewhat complicated as I had to transplant the Windows 98 partition from an old machine on its way out to her new Dell Dimension P4. I got all of this working and the drivers installed etc and left her happily using it.

About a year down the line she managed to infect the XP partition with a range of viruses/spyware. Since I didn't have enough time to fix it myself (and am living a few hundred miles away now!) she took it to a local independant computer shop. They gave her a quote for sorting it out of £115 inc. VAT.

When she came to collect it a few days later, they said that it was impossible to get
Windows 98 running with all the drivers and she'd have to get someone else to do it. (This is untrue, since i've done it!) They still charged her £115 though and being the timid non-technical type she is, she paid.

Now the Windows 98 partition was never a problem - the viruses were only on the Windows XP side. They've left her with an unusable installation of 98 and effectively charged here £115 to install XP and stick some service packs on.

It occurs that given the botched nature of the job, she ought to be entitled to at least a partial refund. Does anyone know exactly what her legal rights are in this case? I'm loathe to fix the PC (which is now in my garage) until this has been sorted... I'm guessing that filing a case in the small claims court is the way forward but I'm not sure about the grounds on which to file a case.

Any advice gratefully received!

All work that you pay for must be completed competently and be worth what you are charged. They must also only do what you tell them and do nothing further.
If you believe them to be in breach of this then they have comitted a breach of contract under Supply of Goods and Services Act 1982
IMHO you're wasting your time taking it through court. If I was the trader I would point out thats 2 hours labour and is about right to investigate, decide a reformat is best and reinstall.

If the person who was doing the repair was asked specificaly to sort out the XP partition only then I would say you have a strong case.

On the other hand anybody that knows about computers should also have recognised that the disk had been partitioned and therefore had no need to touch this partition which to me is lack of experience.

I also have to ask was he supplied with the original xp and/or win98 install disks to be able if the worst came to the worst that he had to do a complete reinstall, and also is he a registered trader.

OK, I'm no legal eagle but here's a few thoughts...

Was anything signed? Is there a detailed bill for work carried out?

When did this happen? If a significant period of time has elapsed since this happened you'll stand no chance.

Can you prove that the work they did destroyed the Win98 installation?