Windows 7: No BSOD, but occasional computer freezing on new build

A brief background: in the last few months I've had a number of BSODs which seemed to generally point in the direction of bad ram. I removed the suspect ram and the BSODs went away. However, I have been unable to replace the ram because new replacement ram is not recognized by the old mobo.

The old system specs are Asus P5B-E, DDR2-800 ram (2x1Gb sticks, 2x2Gb sticks), Intel E6600 cpu, Windows7/64. I was able to rob another system in the house to give me 4x1Gb DDR2 ram (a mix of DDR2-800 and DDR2-533) which allowed me to keep the system going. The bad ram being the 2x2Gb sticks.

Wanting to free up the ram to keep the other system alive, I elected to rebuild my desktop with a new Asus P8Z68V-Pro, core i5-2500k with a CM Hyper 212+ cooler, and 2x4Gb G.Skill DDR3-10666 ram.

The system needed a few program tweaks but seems to run fine... most of the time. But I have occasional system lockups... sometimes just a program lockup (like Firefox), sometimes the computer freezes (even changing user accounts), I even had trouble after uninstalling Foxit, rebooting, and installing a new version of Foxit. It ran for a while and then just quit working. So I used another PDF reader without issue.

These random events had me attempt to repair the Windows7 installation by cranking up the optical drive with the Windows 7 disk during a reboot. But system recovery did not show an OS in the window to repair, wanting me to install drivers. It only wants to restore using a system image created earlier (not that I recall doing that.)

So I cranked up driver verifer (I did have a lot of new drivers to install) but the system immediately froze as I loaded Speedfan 4.44 with some sort of external error. I cranked back up in safe mode to be operational.

Any suggestions on how to sort out this random craziness? I was hoping to avoid having to reinstall Windows 7/64 and all the programs with my custom tweaks. The OS install is no big deal. But recreating all my program tweaks will be maddening.



Oh yeah, I'm not running any OC (but may play once I get this squared away) and the OS is installed on an Intel X25-M 80Gb SSD with a couple of SATA drives for data and storage.