Physical Memory dump

I have only had the system since 18th Sept 04 and as I moved house on the 1st OCt have only just really had a chance to have a play around with it in the past couple of weeks.  Yesterday I wanted to test the DVD&RW and CD-RW and it was when i started this that I started to encounter problems. Firstly the system crashes and the blue screen comes up every time I try to right click on my CD D: Drive, and secondly when i was trying to burn info on a DVD it was telling me that only A DVD ROM existed when I have a DVD&RW and was using DVD&RW discs. I dont know what is at fault but now the whole PC does not seem to be functioning - it regularly has the blue screen and crashes taking the physical memory with it and has the "your system has recovered after serious error" each time i boot.  I am extremely dissapointed as I really havent used the PC hardly at all,all hardware (inc DVD/CDRW), operating system (XP)and software (pre-installed) was supplied by Dell and I certainly didnt expect it to develop faults like this so soon.  PLease help!