ok i have 512 megs of corsair 3200 c2pt or sumthing like that my mum got me another stick its 512 and she got her friend to get it and he said its compatable but the issue im having is that i put the new ram it and it shows up in system info that i have 1 gig so im happy everything works fast. but every now and then my pc freezes and after i restart it it only shows up 512 megs of ram so i have to take the case of and take out the ram and put it back in again any help would be nice

Sounds like the RAM isn't seating into the memory slot properly. The loose connection is causing it to freeze up and then, once it's rebooting, the BIOS doesn't see the second module because it's not connecting properly. When you take the module out and re-seat it firmly into the motherboard slot, the BIOS sees it all properly and reports 1Gb again.

When you push it in, make sure the memory pushes in firmly along the whole length of the memory module. The little clips at the end of the slot should, in theory, close shut when the memory is seated in as far as it will go. In reality, they don't always clip shut completely but you should at least see that the clips move in a bit towards the closed position.

When you re-seat the memory, does the motherboard flex under the pressure? If the motherboard flexes, it's much harder to get the RAM pushed into the socket fully. Home-built systems often suffer from this, due to not having enough support underneath the board. Quality factory-built systems shouldn't have this problem.

Give it a good check over, re-seat the memory firmly as described and let us know whether it's any better

well i took the case apart and reseated it like you said no probs yet and no the mobo dosent flex under pressure. i havent had any probs yet but then again it was about 1 month before the last time the ram screwed up so all i can do is wait :P

well it did it again the rams not showing up i guess its time to take the pc apart again and take it out and put it back in again

Don't know whether you've tried this already but it might be worth swapping the RAM around so that the module that keeps popping out is fitted into the slot that doesn't usually have a problem. You might find that helps it stay in there for longer.

well i managed to convince my mum to getting me another stick of corsair sms 3200 c2 pt pike my other one instead of using the generic stick :P and hey if the corsiar works ill have a gig and i can still use the generic if its a bit more stable and have 1.5 gigs YAY and if the generic stick ****s up then ill still fall back on the comfortable 1 gig

OK but, even with 3 memory modules to choose from, you might still find yourself with a motherboard that has one or more loose DDR-RAM slots that keep ejecting the memory that's fitted in them