OK, just found out I have some software that will not run on SP4, runs OK on SP2. I also need to have at least SP3 for some Adobe software.

Well what I did was upgrade from SP2 to SP4, and didn't archive the old SP2 files. Can I simply run the SP3 updater and have the files go back to SP3, and then sp2 if that software still doesn't work?

I'm going to try it, 'cause if it doesn't work, I'll be formatting and reloading anyway. But I'm not going to do that until tomorrow, so thought I would ask. Actually, I might run the repair option for install. That will get me back to SP2. But would still like to know if this has been done. Thanks.