Hi Nev, Thanks for this advice. My computer is VERY old - 1999 vintage in fact. (LOL). ( It is a Mesh, and cost near on a grand for what, these days, would be very basic rubbish. (It actually ran under BASIC). How technology has moved on since my Sinclair beginings. 8K of RAM, which I doubled to a staggering 16 KB!!) I did a major rebuild somewhwere around 2004, new MB (Asus Rock), CPU (Athlon XP 2000+), PSU, Graphics Card, Sound Card, RAM (now 2GB), Hard Drive (40 GB), USB 2.0 Hub. At that time I installed Win XP, but only upgrade vers from Win 98 SE. I have since installed SP2 and SP3. Hence, I have no complete disc to carry out a repair, though I do have a Win XP Pro disc which I picked up very cheap, it is a Dell original and I have the Key for it. My thoughts were to install a second Hard Drive of the largest capacity my old set up could handle then run both XP versions. A lot of effort to achieve not a lot, and my real aim is to build a new machine entirely, or even, if my tiny pension ever goes into surplus, buy a new one! Meanwhile I have ordered a LCD monitor to replace my original 200 kg CRT Mitsubishi, on which the RGB drive is failing. Computing at the cutting edge eh?......... For the corrupted file problem my original question still stands, - as I have upgraded to IE8, can I get rid of IE7? That would remove the problem file and I would at least be able to run a full AV scan from time to time. Finally a supplimentary question: on this website (freepchelp) I get a message that "An add-on for this website failed to run. Check security settings in Internet Options for potential conflicts". This I have done and find no problem. ?? Thank you for the help. Brian.