Turned out that the PC just needed a good clean (dust free).
As my new graphics card needed a minimum of 300w i also upgraded the PSU to a CWT 405w.
So i 1st installed the new CWT PSU, i turned on the PC (before installing the GPU GT 240) and everything was working fine.
Next i installed the new GPU (GT 240) and this is where my problems started.
Basically if i boot up with 4gb ram i always get a BSOD and the PC restarts itself, and then i may get the same BSOD again or i just get a black screen in which i have to turn the power off to get rid of.
If i boot up with 2gb ram i have no problems at all and the PC works great?
I have tried both 2gb sticks seperatly and they both work. My motherboard has 2 DDR2 slots and aslong as i only have 2gb ram installed it doesnt matter which slot i use (i have tested them both) I have run memtest on both sticks and both came back with no errors.
I have searched the net for an answer and the only one i can find doesnt work for me as i cannot even get into safe mode when i have 4gb installed, the following link is what i found:
As the 4GB DDR2 PC2 6400 800MHZ was oem samsung memory, i have also brought (& awaiting delivery of) OCZ2G8004GK gold series. Do you think i will have the same problem when i install this memory? I think i will so i would like to get this problem fixed before they arrive. A few other websites say try and reinstall windows, but i would like to save that as last resort.
I have posted this question on a couple of other sites and there are quite a few saying that it could be the PSU so i think you may be right.
I only brought the PSU from a local PC shop on friday so i'll take it back and get a 600w one.
I will try the tool and see what the outcome is, but like i said above i do believe that the PSU may be the problem and i'll change it for a 600w one.
Yes the PCI-e slot is 2.0 i forget where i have seen this on the PC (may have been when it is booting up or on the control panel somewhere) If you know where to find this out i will have a look and let you know, but I have played Virtua Tennis 4 for about 2 hours with no problem with 2gb ram so i dont think there is any problem with the GPU.
I've never heard of a CWT brand PSU... if you can, get a quality brand like Corsair, Antec, Seasonic, Cool Master, etc. When it comes to PSUs, you really do get what you pay for. I wouldn't be surprised if that's causing the issue.