Windows 7 32x Locks Up Randomly - SF Diag Tool File Attached

Hello All -
I inherited a Windows 7 machine because it 'has issues'. I started from scratch and reloaded Microsoft Windows 7 Professional 32x Ver: 6.1.7601 Service Pack 1 Build 7601. It works well except it regularly freezes (i.e. It has no recognition of the mouse or keyboard) randomly: either while Windows 7 is loading (stops at logo screen) or can happen any time while in use. This also occurs when the computer is left ‘on’ or in ‘power down’ (sleep) mode overnight. I have learned, *if it freezes while booting*, this works: Hard shutdown, reboot into Safe Mode then do only a "Restart" and it works fine. Until another random freeze.

I've checked my RAM: All is fine
Check Disk: No Problems

Does anyone have thoughts or suggestions?
Thanks for taking a look at this post.
/jdU

Yes I ran Memtest86+ overnight (16 hours) and 8 full passes with no errors.
Any suggestions on what to try next?
Thanks!
/jdU

I just realized I forgot to attach the SF Diag File ... now attached.
From it I extracted this:
Total Physical Memory: 3,070 MB
Available Physical Memory: 1,402 MB
Virtual Memory: Max Size: 6,138 MB
Virtual Memory: Available: 4,448 MB
Virtual Memory: In Use: 1,690 MB

/jdU