Wow, my system crashes hard - right after login! I've heard about quite some crashed with Ubuntu 12.04. ... any suggestions on how to proceed?
Here is the link to the logfile of Boot-Repair - which I tried without success (details see below):
http://paste.ubuntu.com/1630291/
Also, running memtest86 from the boot-up program resulted in 0 errors found. Neither, did a check on the harddrives yield an error message.
Further Details
Ubuntu will boot fine up to the login screen. Then - after I enter the password and hit login - it will hang. I am not able to enter anything at the resulting screen (see image - larger view here).
The first time this occurred was right after I cleaned my computer carefully with aerosol. Maybe a hardware damage? But I don't think so, it was minimal maintenance mostly focusing on the cooling-fans. Also, I removed an old harddisk (no boot partition, just mp3 data).
Regarding Boot-Repair ... ran it through UbuntuSecureRemix (a Ubuntu boot mix CD) a and used the standard option "Recommendend repair - repairs most frequent problems".
Ok, got back into my system and it is running.
To help others, here is the simple fix:
All I had to do is boot into an older kernel! :) (here is an explanation on how to do it https://askubuntu.com/questions/97731...keeps-crashing )
Note though, that I had to go back to a kernel as low as 2.6.x. I won't reinstall for now - there are too many issues reported with 12.04. or 12.10. - but if I notice unusual behavior I will. Now, is a good time to run another backup on /home.