Hi, mate try this, if you have not done it already?
Restart you pc, and keep pressing F8, this should bring up a window with tools you can repair its startup programs, or totally reboot you computer but make sure you backup your file first.
f8 is safe mode on most computers,you would probably be better trying f10 or f11 as that should give you the recovery console where you can try to repair Windows/put the computer back to factory settings.
i upgrade the memory to 512 over a year ago. No probs until now. I have a really dodgy USB port at the front. It has a loose connection and anything connected to it sometimes becomes unconnected.
sorry spaced, 512 is okay although that depends on how much stuff is on your comp!, that said vhelpful guy is right that you need to look at any problems with hardware and software.
some bluescreens are caused by different versions of dll files and badly written drivers, have you made any changes to your comp recently? (reinstalling drivers, changing hardware ect??)
When you get a blue screen there is lots of text on the screen as well, it is worth actually reading this as it is reporting to the best of windows knowledge what the problem is. although it is not a guaranteed way of pin pointing the problem it can often help in steering you in the correct direction to look.
Next time you get one of the infamous blue screens make a note of what it actually telling you and post it and someone may be able to give you an indication of where to start looking.
That said, at 4 years and given the fact that you have a dodgy USB port probably isn't far off the time to be considering a new 'puter.
Pull the memory out and reinsert it making sure it is properly seated. Be sure to disconnect the power before you do it.
Also check the capacitors on the motherboard. Your computer is just the right age for this quite common ailment caused by a vast number of capacitors made with faulty electrolyte a few years ago.
See this site dedicated to the problem with advice on diagnosis and repair.
www.badcaps.net/
Gawd ... don't do anything suggested here except the first para of chuck's reply.
2-4 GB of ram ... a 4 year old machine won't see more than two (if you are lucky) ... 70% of the world regards 512-1 gb to be a lot of mem
Start by googling the specific BSOD (but don't expect to understantd too much of the results)
BSODs are anything that causes your 'puter to crash in a way which can't be recovered.... often because windows can't "think" - which in real terms is create temp filed
it could be memory but it could be the HDD... it could be overheating (easy to check ... 4 years is a lot of dust).
it could be a corrupt driver, it could be the last chip on your dimm ... (take note of what prog(s) are running at the time)
without the code ... it could be just about anything
after 4 years consider a backup of data .... and a rebuild of your OS (I do my main machine about once a year) esp if you "play" with a range of progs