chkdsk is a good utility but once in a while it will destroy things while trying to fix problems. If that has happened, you won't have much luck trying to fix the problem short of running a system file check to repair/replace any damaged system files. You will need a regular XP install CD or if it is a system that only gave you a 'recovery cd', you have to hope for an I386 folder on the hard drive someplace. If you have either of those, click on start => run
, key in
and click OK. It will run pretty quickly and silently in most cases.
If SFC fails to correct the problem or if you can't run it, booting from whatever XP CD you/she has and doing a repair install is about your only option.
If you have a regular XP CD and if all goes well with it, you should not lose any data or programs but I like to burn copies of any critical items to a CD anyway.
Note that some of the systems that only give you their own version of the CD will simply re-do the system back to the defaults when it was new and data/programs could be lost.