I just backed up all my files to cdrw and then formatted the drive...back up and running now and have restored all the cds except one which copies for a while and then says invalid ms-dos function...anyone know what this means?

windows tends to throw up that message when it cannot understand the format of the file your copying. For example, it will do it often with VCD's, since the data is stored in a similar way to a audio cd.

Did you reinstall XP, or just try and copy it from the cd backup? Because if the later it wont work, you'll need to install xp, then restore the stuff from your cd.

A tip, when copying from cd to HD, make sure once the files are coppied you remove the read-only attributes from the coppied file, this can be done by right clicking a file/directory, select properties, then untick read only.

Good luck!

I installed windows from the original cd. It seems to be what somefreak said to a certain extent for example a couple of the files were PDF's and without acrobat reader they won't copy, installed arobat reader and now they copy fine. It's not the case with all the files though