PC slows down and occasional crash

Sorry there has been no replies from me as i have been away for a while and only been back this week

I come with bad news im afraid, the PC seems more sluggish then ever and so i decided last night to run memtest again, whereas it passed before last night i was getting continues errors, i have posted the images for you to see.

I have contacted the supplier Microdirect where i bought them from and they said to send them back for analysis however if they are deemed working i will incur the costs, so i want to check that you think it is indeed the RAM and with these latest tests i believe they are.

After testing out my RAM the company i bought them from agreed they were faulty and was giving errors and have since replaced them.

However after installing them today i got a BSOD!!

This is what BlueScreenView showed-
SYSTEM_SERVICE_EXCEPTION
Log attached, really frustrated now as there was deffo errors with the old RAM but the problem still seems to be there.
I will re-test this RAM as well just in case

I have had to go back to XP the crashes were getting more frequent and nothing was solving the problem.

I have now been running XP for nearly a week now and have had no problems what s ever so im presuming its a WIN 7 fault.

Its a shame really as i loved that OS but id sooner have one that doesn't crash so often.

Will i just have to put up with XP for now do you think?

Still having this trouble and it has been suggested to me that its a possible Hard Drive fault.

When i say fault i mean it was said to me that seeing as my hard drive is a Cavier 'Green' drive it only spins at a max 5400rpm compared to the usual 7200rpm, thus being slower when installing etc

Does this sound like a probable cause to anyone as i dont want to fork out for a new HD if this doesnt seem correct?

i did try and use my old IDE drive which spins at 7200rpm and must say i didnt really notice any lag, but its very old (about 8years) so dont want to rely on this one in case it packs up as its very noisy.