How to change 64 bit os 7 0 to 32 bit?

apart from the 4GB RAM Limit dont think there is any hardware problems involved as long as you can get the drivers

but post your system spec. for better answer

Processors have had 64 bit capability for quite some time. There should be no problem running a 32 bit OS on it.

As they said above, it is no problem. However, since Microsoft no longer supports XP, many motherboard manufacturers no longer include XP drivers. So if this is a new machine, make sure there are XP motherboard drivers available for it.

As mrfatbox says - post your system specs to get better answers.

As mentioned above, the biggest concern is find the appropriate Windows XP drivers for the motherboard. If the motherboard is fairly new, then chances are the manufacturer will not have the appropriate Win XP drivers for it.