If your Dell has a Recovery Partition, you can hit Ctrl F10 when you see the blue bar after the Dell BIOS splash screen.
Hope this helps me too. I have the same problem. I installed XP PRO OS from an OEM, (I was not able to use the keys from My DELL OEM OS Sticker, Have to use the one came with CD) and runnig fine, but now I can not access any of my old programs, I do see them in my C:/Programs folder. Any guidence?