As shown in the manual, if # 3, and 4 are lit on front of that system, and not the other two ( Correct ?)......." Memory modules are detected, but a memory failure has occurred "    Not 100 %, but your memory might be bad.  Turn off the system, unplug from wall, push in on the front power button to discharge the system further.  Open the case, and remove both memory sticks, than reseat one stick only ( Firmly), and try to boot up.  If it does not work, the memory might be bad or the memory slot might be defective.  So, turn off the system again, open the case, and place that same memory stick in the second slot to see if it works.  If it does, than perhaps the memory slot is defective, and you need tech support.  If the stick does not work, than the memory is bad, and has to be replaced.  Do this all over again with the second stick, to see if that one boots up as well.  If not, its a bad memory.   If both memory sticks work, than it might just have been a loose connection.   Sometimes this happens.   If it does not work, than follow the instruction on this link to trouble shoot the issue, or call Dell for warranty service.  Good luck.

 

http://support.dell.com/support/edocs/systems/dim3100/en/sm/adtshoot.htm#wp1124478  Trouble shoot for your system

 

Dim 4400
2.6 Ghz 400 FSB
1 Gb 2100 DDR memory
Windows XP Home
120 Gb Seargate 7,200 drive
24 inch 2407 WFP
XFX 7800 GS O/C AGP
Dual 16x DVD-R
410 watt ( PcPower&Cooling )
PC-Cillon Internet Security

Come back onto this thread and let us know of the outcome.  Would be interested myself if I was right or wrong.  Good luck with it  :smileywink:

Oh cool! Memory stick shuffle! I've done that! (just wasn't there to see the beginning symptoms, so didn't know)

 

Thanks! :smileyvery-happy:

You were right. :smileyvery-happy:

 

I reseated the memory cards and it's working fine, now.

 

Thank you so much!

Great news.  Simpler that we thought it would be.  Good luck