Try going to the users control panel (in safe mode) and make sure that you have administrative rights. Also you can try and create another account to log into windows from and see if it is your profile that may be corrupt. If you can log into windows without problem using another *new account than your previous one has the problem (software or corruption).

Thanks for your answer.
I created new User Account with Administrative rights in Safe mode, but I still can't log in using that account in normal mode...
It just loggs me off before I am logged in...
So there's probably something wrong somewhere else... And accounts seems to be all right...

I have seen this happen a couple of times, only in Windows 2000 tho. You need to delete the account, and the files in documents and settings, and recreate the account with a fellow admin account.

Ok, normally I would agree w/ the delete and re-add account, but he already stated that he created a new account in safe mode and it too suffered the same problem.
 
Not really sure if this is your problem, but when you are in safe mode, go to start -> run type in gpedit.msc and <enter> When the group policies MMC comes up, go to computer configuration -> Windows settings -> local policies -> User rights assignment -> look for Deny logon locally and see if administrators or any groups/users are listed there for some reason.
 
If there is something listed there, I'm not totally sure how you get in under safe mode, but that is another matter, you will need to remove whatever is in that list and then right click on security policies and click reload. Then reboot the machine and try logging in again.

Hi thanks for answer...
But I think that Home Edition does not have Group Policies Editor... To I am unable to check User rights assignments...
But I think it's everything okay with User rights...
 
I have newly installed Windows and now everything works okay...
 
Thanks for everything...