Ok I just installed a GeForce MX 4000 128MB DDR Graphics Card and looking around my system info i noticed that my ram had gone down from 512mb to 256bm. I have two separate 256 sticks of ram. After a restart it wouldnt accept one ram stick anymore (256mb ddr-266mhz). I uninstalled the video card and it still wouldnt accept the memory stick. I've tried starting up my computer with only the "bad" stick of ram and all I get is a blank screen. But the other stick works perfect. Could it be that my 256 stick of ram has gone bad? Is there something i can do to fix this?

first make sure that the ram is seated securely, if you have more than 2 slots (of the DDR variety) try the ram in different ones.

you may have lost the questionable stick coincidentally at the same time, or maybe you shocked it when installing the video card

judgeing by the components mentioned this seems to be an older system. the good news is that to replace one unit is under $20 on newegg,com or getting one 512mb stick is ~$40

I agree with Gothmoq. I believe you have had a memory module failure. Install both modules and run MemTest86. It will tell you the status of each module.