fix computer errors

I just recently bought a new processor at Microcenter, The Intel E5200 and my computer would give me the blue screen of death. My pc would just freeze and give me an error. Even during reinstalling XP i would get the blue screen. It is the 4th or fifth time of a clean install of XP on my hard drive. I did checkdisk and other programs i used to see if my hard drive had problems but my hard drive is fine. I swapped out the memory and my pc would still crash. I just put in my old celeron back in just now and my pc did not crash or freeze. My motherboard is a Biostar G31 M7 TE and it supports my processor from celeron and the exact model number for the E5200 all the way to quad core. I did not overclock or anything to my processor. The error i would get at the BSOD is Stop: 0×0000007A (0XE14D58C0, 0xC000000E, 0XBF90F00D, 0×7990A860
another BSOD said Kernel_Inpage_Data_Error
and also Win32K.sys-Address BF90F00 base at BF800000, date stamp 41107F7A
I saw on a thread on techguy that a processor could have compatibility issues with ram and i think it might be the case. As i speak right now i am using my Celeron 440 2.0ghz and it has not frozen or crashed yet. If i was using my E5200 dual core, even if i left my pc idle the cursor would freeze and the system would crash. I checked device manager and It has support for dual core. This is a custom PC build that i bough all the parts separately. Please help
already updated bios.
my pc keeps crashing and i found out doing research that it could be my memory causing it. 1st, the memory is two different brands. 2nd one ram is DDR2 PC26400 and one is DDR2 5300. I am using my celeron right now and its working fine but if i put in my dual core it would keep crashing. I heard that If you buy memory it should be the same speed according to my motherboard manufacturer. For example I have a dual core Pentium E5200 with a 800mhz fsb. So that means i should get PC2-6400 DDR2 at 800mhz right? Trust me i tried everything, i reinstalled xp llike 5 times. Its not my HD or drivers. Please help.
I also found out that both of my memry is single channel. One is Avent DDR2 PC-6400 800. Is this a generic Brand? My other ram is Kingston DDR2 PC-5300 667. Even when i swapped an only used one of each my PC, sound, audio and video lags, jumps, and skips. Shpuld i get new ram that comes in a kit of two identical rams for example http://microcenter.com/single_produc…u… or http://www.newegg.com/Product/Produc…8… or http://www.newegg.com/Product/Produc…8… or http://www.newegg.com/Product/Produc…8… which one would you prefer?