Hi, A few weeks ago I upgraded a Sony Vaio Laptop (model PCG-FXA35/D) from 256MB (two 128MB sticks, PC100) to 512MB (two 256MB sticks, PC100). It started freezing up several times a day. It had been fine on the two 128MB sticks. I replaced the RAM again with two different 256MB sticks, but it still freezes up. I've formatted the hard drive and reinstalled Windows XP, but it STILL freezes up! It doesn't seem to do it when I do anything specific; it seems pretty random. Also, I checked the manual to see if there was a RAM limit, but according to the manual, two 256MB sticks should be fine. Before I spend another $100+, is there anything else it could be? Thank you so much!

Try checking for a bios update...i upgraded a vaio laptop for a friend from win me to xp and had numerous probs....after i got the bios update it was fine.have you tried putting the old ram back in? if you put it in and all is good then you probably have a ram conflict with mobo.

Original RAM was fine. But as I said before, I've replaced the RAM twice so I'm not sure if it's a RAM problem. Checked for a BIOS update at Sony... all they have is the version I'm running right now. Any other ideas? :(

well if the old ram runs fine then it has to be something about the new ram that xp doesnt like....xp is very picky about ram sometimes. maybe try another brand name. is the speed the same as the older ram? and if not is (assuming the new ram is faster) is it backwards compatible with the slower speed. i would start by searching google for that model notebook and insert the words "ram upgrade" or something similar and see if others are having the same problems upgrading the ram in theirs. maybe someone else has figured it out.

The original RAM modules say "Hynix" on them. I think I first tried Kingston 256MB modules for the upgrade, but when that didn't work I tried (and am using) Kingmax (or something like that). They are all PC100 speed. There's not much on Google... *sigh* This is a terrible problem...

You'll need to make sure they are the same type, eg. unbuffered, non-parity. The number of chips on each DIMM will help with this. If you have twice as many chips on one, then try just using one DIMM to see if it works OK with only 256 on one DIMM. You may wish to try the old 128Mb DIMM with one of the new 256 ones. Various combinations and simple logging of what you've done on paper will help you diagnose if it is a faulty module or a configuration problem. Be prepared to spend some time on each confirguration you try. If you have any doubts at all about your BIOS version, I mean ANY, as BIOS version and date modification is so easy now, download the latest (even if it's the same) and try it. Reset your BIOS to its default. Keep trying the old and the new together, as you may find that one is faulty, or that there is a unique config problem with certain situations. (Eg. the Abit BP6 often had problems when a 3rd DIMM was installed when a 256Mb module was in the first socket.) Just some ideas. I troubleshoot by elimination if I can't find a solution from somewhere else. Don't try anything you're uncomfortable with, research it first. Take your time, record your findings and you will probably come up with your own perfect solution. It's laborious, maybe time-consuming, but if you want to really learn, it feels great when you learn something by yourself and it sticks in your mind for a long time. (I had a BP6 until not long ago, even went as far as soldering my own components to it. It now supports dual P3s in my future parents-in-law's computer. Perfectly stable now, as I have been working on it using my methods above for over 5 years.) Mike P.S. Stay sane, take your time, don't take up smoking, or drink too much. Record what you do and make your own solutions if you can't find another's to learn from. You can do a lot with nothing... look in to space, what's there?

Hi, Thanks for your help. LOL, I'm not going to smoke or get drunk... I'm only 14, after all :)