PC hangs on POST screen/memory testing

[chip09031998]

When I turn on my PC it hangs on the POST screen where it does memory testing. I can't get into BIOS settings and I've tried to do a full system recovery but it also hangs on POST screen when I try to do that. I have also tried a different CPU, only one RAM module in different RAM slots, different RAM modules, taken out my GPU but still to no avail.

Could someone please help so I can find a solution to the problem and what needs fixing.

My PC specs are:
CPU- Intel Pentium D 945 Dual Core @ 3.4GHz
RAM- 3GB DDR2 RAM (1x 1GB module & 1x 2GB module)
GPU - NVidia GeForce GT430 512MB PCI
Motherboard- Foxconn N15235
OS- Windows XP SP3
HDDs: 80GB (C:\ Drive), 120GB (D:\ Drive)

 

[Xttony]

Have you tried resetting the bios to the default settings?