Is thankfully discussed widely. Let's get you pointed to those discussions at http://www.google.com/search?hl=en&source=hp&q=windows+7+corrupt+profile
BUT first you should backup what you can't lose before attempting any repairs as the damage reads like something recent trojans and malware does to machines.
I'm on a HP C40-621LA with wind 7 home premium, today i got a power blackout on my block due a rainstorm quite strong.
Because of this, the computer turned off since i use it w/o the powercell to avoid least-longing of it. . .
Anyways, the light came on, turned on the computer, began to load and, SURPRISE!!!, went to the black checkdisk screen saying that windows shut itself improperly.
Logged on to the user's desktop to only find that virtually ALL SERVICES didn't initialized (wlan, win explorer, i.e., messenger...)
Shut down, led it cool, started again with the checkdis black screen (2nd time around).
Then loaded the profile selection, typed the pass and couldn't log to the desktop, saying that the files for the profile were not found, try again later or sign up using a different profile.
Tried later only to log on to another checkdisk black screen (3rd time).
The profile selection screen loaded, typed the password and, BIGGER SURPRISE!!! my desktop background isn't there, nor my icons, neither my desktop files (all gone to dunnowhere).
Also, a "cute lil' popup window" emerged saying that all mine files will not be saved, nor any work i do on that profile. That i need to change the profile or try again later. Also says to check the event log to see more detailed info.
Checked the event log and, since the blackout, is full with red exclamation marks saying "error" in different modules of windows, from svchost.exe_Sys main to svchost.exe_CryptSvc to catalog database.
Please, tried to meny things already to overcome this unexpected fail, that i'm dry...
If need further data please contact me@ firstname.lastname@example.org