I need help to recover from error-physical memory dump

I need help! I have a dell inspiron 5150. Was working with it last nite on photos and it seemed to freeze on me. I pressed the power button. waited one minute and restarted and it went to the screen with the recovering from serious error. Restart and use safe mode if this hasn't happened before....I use windows XP Pro. I restarted, pressed safe mode and it took forever and then began to run through the mode. Then I got C0000218 Unknown Hard Error...Beginning Dump of physical memory. I turned it off by closing it because I was afraid I was losing all my work for four years. It had been getting hot before this occurred but I refurbished it just last year with a new mother board using the same 80 Gig HD and other essentials. Now, my memory fails me at present and I cannot begin to figure out how to recover from this...any help out there would be appreciated.