Thanks so much for your help.
My oem xp included sp1, so I ran the remover of the .NET Framework. First and only success.
I could not download xp3 in your link. The download stops straight away. Not sure if this is the reason, but I keep getting the following error message with just about anything I try:
"the procedure entry point decodepointer could not be located in the dynamic link library kernel32.dll"
.Google says its because my sp is outdated, so here we go with the circular catch 22 again.
Anyway, I downloaded another xp sp3, but it is iso file, so I downloaded two different unzip utilities, one was installed but doesn't want to work, and the other one does not want to install.
So I am stuck again.