Dell wont boot past windows xp logo

Have you tried safe mode? To get to the Windows Advance Boot Options menu, immediately and repeatedly hit the F8 key after powering on. From the menu, select to start Windows in Safe Mode.

After Windows boots into safe mode, hit Start -> run -> type in "msconfig" into the blank box and then press Enter.

This will bring up an advanced boot option menu in Windows. From this menu you can see what applications and services are starting up when Windows starts. Disable any that aren't necessary.
 
Have you tried calling tech support? Why pay extra for it and not use it?

To be of any help, we need the specs. Give us the exact model of the components when available.

What have you tried doing? Have you changed anything in BIOS? Have you added any new parts? We can't do anything if you don't tell us anything about the problem or machine.

At this point, it could be the CPU overheating, the RAM gone bad, the PSU failing, the motherboard failing, a corrupt Windows installation, a HDD gone bad, or any number of other problems.