Optiplex 320 Memory Issues!

Ok, updating this post for the new forum:

 

Dell Optiplex 320

 

Intel E2160 (Dual-core, 64-bit) 

 

4 gig RAM (currently 2 gig, read on...)

 

160 gig HD

 

Video: ATI Radeon Xpress 200 (integrated) Radeon X1300 256 mb PCI-e 16x slot <--where the issue started

 

OP System: Windows XP 64-bit

 

BIOS: Latest 1.1.11

 

Drivers: All the latest, working no errors!

 

 

So basically when I installed the 2nd Radeon card in the PCI-e slot, I discovered that my computer ran miserably slow, or wouldn't boot at all.

 

Dell was no help, they though my motherboard was "bad". So they replaced it per warranty, which made no difference.

 

Finally got a suggestion from "momdog" on this board, suggesting I try it with just one of the two, 2gig DIMMs I had installed, and it worked perfect: NO ISSUES except I no longer have my 4 gig of memory (which would help me a lot in some cases: ie. games)

 

Now "momdog" suggested I load windows once, run all updates, than re-install the 2nd DIMM and I should boot fine, no luck though! Same old issue.

 

So what's up? Any ideas...? Since I didn't have this issue prior to installing the PCI-e card, and was able to run both memory DIMMs I believe it has something to do with the way the system BIOS allocates resources between the RAM and the PCI-video bridge! Ideas, fixes, all will be considered!

 

Thanks!