I've read through dozens of possible solutions on the web. Can't believe there are dozens of possible causes to this vexing problem of a blue screen after doing a Vista log-in.
I was about to render my laptop a very expensive frisbee out a 10-story window. Thanks to many well-meaning souls out there who came up with their own solutions. I tried one after much trial and error and solved this problem (I realize not everyone is going to have the same cause/solution).
What worked for me is here:
Boot to safe mode with command prompt.
Type the MSCONFIG command, disable all startup programs and disable all services.
By process of elimination, I found the culprits to be Windows Event Collection and Windows Event Logging.
Still using MSCONFIG, I disabled them, re-booted, renamed \windows\system32\winevt\logs\system.evtx to \windows\system32\winevt\logs\ystem.evtxOLD, re-booted.
Enabled the two previously disabled Windows Event services in MSCONFIG, re-booted.
After logging in, checked Event Log in Control Panel/Admin to make sure it was working. MSCONFIG is a life saver.
Again, my thanks to those who have toiled with this problem and offered their solutions.