Hi Abraham Lingga,
1) What is exact\complete error message that you get?
2) Do you remember making any changes to the computer prior the issue?
Method 1:
Firstly, I’d suggest you to uninstall the antivirus program and disable firewall temporarily and try to perform a system restore and check if that fixes the issue.
Refer the link below for more on uninstalling programs:
How do I uninstall antivirus or antispyware programs?
http://windows.microsoft.com/en-us/windows/How-do-I-uninstall-antivirus-or-antispyware-programs
Note: Antivirus software can help protect your computer against viruses and other security threats. In most cases, you shouldn't disable your antivirus software. If you have to temporarily disable it to install other software, you should
re-enable it as soon as you're done. If you're connected to the Internet or a network while your antivirus software is disabled, your computer is vulnerable to attacks.
Turn Windows Firewall on or off
http://windows.microsoft.com/en-us/windows7/Turn-Windows-Firewall-on-or-off
Note: You should not turn off Windows Firewall unless you have another firewall enabled. Turning off Windows Firewall might make your computer (and your network, if you have one) more vulnerable to damage from worms or hackers.
Method 2:
If the above steps do not help, try doing a system restore from safe mode and check if that works fine.
Refer the below link for more details on starting your computer in safe mode:
Start your computer in safe mode
http://windows.microsoft.com/en-US/windows7/Start-your-computer-in-safe-mode
Method 3:
If the issue doesn't occur in Safe Mode, perform clean boot.
How to troubleshoot a problem by performing a clean boot in Windows Vista or in Windows 7
http://support.microsoft.com/kb/929135
Note: Do not forget to return the computer to normal after completing the troubleshooting by following the step 7 from the KB article mentioned above.
Also see:
System Restore: frequently asked questions
http://windows.microsoft.com/en-us/windows7/system-restore-frequently-asked-questions
Note: When you perform System Restore to restore the computer to previous state, programs and updates you installed are removed. System Restore helps you restore your computer's system files to an earlier point in time.
