Was away for a few days.
On return Windows prompted me to install (though not the normal monthly that was done earlier in Feb) some updates including Microsoft Security Essential (MSE).
The update seems to have broken something.
Safe Mode symptoms:
1. Boots fine
2. unable to uninstall MSE (which I think is actually normal).
Normal mode Symptoms:
1, System boots in normal mode, seems to have the high res drivers at login screen though more sluggish with "wait" mouse pointer circle that normal
2. After login in normal mode, just get a black screen with white mouse pointer. Can manage to get task manager by using CTRL+ALT+DEL, and selecting it from the "logoff" menu, but not much else. The system seems to hang/waiting on starting a MSE/Anti malware service.
3. Started with diagnostic services only in MSCONFIG (using safe mode) normal mode gives errors that appear to be related to a profile service being unavailable). Just get the start button and trashcan but not much works.
I suspect MSE update has broken things, and because safe mode does not do runtime protection it boots okay.
No disabling that whilst safe mode did not help, and I was not able to uninstall MSE even with an RGY hack to allow the MS (un)installer service to work. Vista Repair, last good configuration, and system restore all no good,