Hello, I am running Windows 7 (32 bit), and I started getting these BSODs:
"A problem has been detected and Windows has been shut down to prevent damage
to your computer.
The problem seems to be caused by the following file: ntkrnlpa.exe
If this is the first time you've seen this stop error screen,
restart your computer. If this screen appears again, follow
Check to make sure any new hardware or software is properly installed.
If this is a new installation, ask your hardware or software manufacturer
for any Windows updates you might need.
If problems continue, disable or remove any newly installed hardware
or software. Disable BIOS memory options such as caching or shadowing.
If you need to use safe mode to remove or disable components, restart
your computer, press F8 to select Advanced Startup Options, and then
select Safe Mode.
At 5+ years old, I'll suggest changing the CMOS battery as a first step here (or at least check that it is at 3v). It appears to be a memory error but I would focus first on the battery since on many Dell (any pre-built) machines, it going bad can have strange consequences (such as BSOD's)