My PC is a Toshiba M645 laptop(Win 7 64). I got a update for my MS Security Essentials yesterday. After that I restarted my system and I was unable to log on to system. I can come up to login screen where I can enter password. But after entering password nothing happens when I hit enter or click go button. It isn't stuck there, because I can restart my pc using restart button. After that I boot pc with safe mode and I was able to login. Then I restored pc to a previous version and after that I was able to log in normally. I disabled that update because I thought that was causing this error. After that I installed COMODO firewall and it request a restart so I restarted system. But again I was unable to login to the system. Then again I go to Safe mode and tried disabling all start-up items and services but no use. I tried registry cleaning using CCleaner and it is also no use. Only working thing is system restore. But after a restore also I cant install COMODO. When the login is not working, I can see my hdd bulb is blinking rhythmically. What is causing this error? How can I resolve this.
If that does not work startup in safe mode, login using Administrator Account and create a new admin user account
restart and login using the new account.
This will find out if old account was corrupted or you have something which affects all accounts
Also while in safe mode schedule a chkdsk scan for C:
There is a hardware diagnostic program available on most modern Toshiba laptops which can check for faulty RAM or Hard Disk which can cause strange things to occur.
If Windows is too corrupted by malware to repair considering backing up all important data to external hard disk, DVD's etc then running Emergency Recovery Procedure to get Windows back to as delivered state.
If you have MS Office or converted Office Trial into full version make sure you have licence key available.
I tried All above options. Nothing works. Checked the hardware and didn't found any error. Tried to log from another account but it didn't even come to welcome screen. Just on the enter password screen.
There is something screwy with your Windows installation it may be better to reinstall Windows than to try and figure it out. You could try running as the administrator from the command prompt "SFC /scannow" without the quotes. If any error is found then it is probably due to a memory error. It maybe a good idea to run a memory test to test the memory anyway, run memtest86 for at least three passes.