dell wont boot

i just got a dimention 9100 that only had 512mn of memoy. againt the advice of dells site i put 2gb of pc6400 800mhz (pc5300 667mhz is supposed to be max) it booted and ran great. afer running for 4 days and then uninstalling software i didnt need i rebooted, but the monitors arent getting signal.

Ive unplugged all drives, removed the dialup moden and even swapped the memory back and the video card for an older pci card.

Ive also removed the cmos battery and left it to reset. but even with only a power supply mobo cpu memory and graphics the monitors lights wont even trn green.

If I remove the memory completly it beeps continuously. but if it has memory it beeps like its booting but the screen never displays. also numlock doesnt respond. is it possible for the memory to have fried the motherboard and yet it ran for 4 days? or is there another solution to this?

 

Hi my friend , what is the programme do you uninstall from your computer ? :wave

 

i removed the expired avast, several games and utilities that i dont need