Since, you already had XP installed, it should be capable to be re-installed. You will need to save any critical data. As you stated, a "clean install" is the best approach. You then install OS, then drivers and then any OS updates, then any pgms. you need. Now, as for pgms. you gave no clue to what was installed(under win7), but if they ran in won7, they should also in XP, unless it *clearly* states otherwise and for now it should though.
*IF*, you did the win7 install and saved the old OS, you can possibility return to it as it was on that date, provided you saved it. It will look for windows.old and when found return to original OS -OR- at least the data from that OS. Thus, you will still need to install the old OS, then retrieve that data, should you want to as an option. Its worth a try, if successful you at least get a running start as things used to be. Vista and win7 will restore data from its own procedure, but XP won't, you thus need to manually do this. In fact, if you saved the old OS when you win7 install, the windows.old folder/file becomes your data source if anything. Be sure to back-up windows.old or just the critial data to CD/DVDs, a clean install will usually wipe out the HD.
I've had enough of Win 7. Constantly freezing now. I want to revert back to XP Pro. What is the best way of going about this?
Do I undertake a full backup, delete Win7 then do a clean instal of XP? Will I find some of my programs will not run on XP?
Some advice would be greatly appreciated.