The stop message means that a memory access violation has occurred (the 0XC0000005 part of the message), see
I suggest that you run the memory tests in the Dell diagnostics.
As far as your BIOS is concerned, for the Dimension 2300, the last BIOS update was A02, in September 2002, so unless you got your PC before that date you probably already have that. You can check by entering the BIOS when you start your PC, immediately before Windows starts loading, press F2 repeatedly to Enter Setup. You should see the version there.
Other possibilities are driver conflicts: have you updated any drivers prior to this beginning, or added/replaced any hardware components?
Precision Tower 5810, Quadcore Intel Xeon E5-1630 v3, 3700 MHzRAM:16 GB PC6400 DDR4 SDRAM 1066MHzHDD: 2x ATA ST500DM002-1BD14 500GB SATA non RAIDDVD:HL-DT-ST DVD+-RW GTA0N SCSI and PLDS DVD+-RW DH-16AES SCSIVideo: nVIDIA Quadro K4200 PCIe 4GBAudio: Recon3D PCIe, Altec Lansing ADA995 5.1 speakersMonitor: Dell E2011H
7.1 pro sp1 64 bit