Hi Romero,
- Do you get any error message/code?
- Is the issue specific to task manager?
This issue can occur due to viruses or conflict with any third party program.
Here are a few methods which you can follow to resolve the issue:
Method 1:
Microsoft Safety Scanner
http://www.microsoft.com/security/scanner/en-us/default.aspx
Note: Any data files that are infected may only be cleaned by deleting the file entirely, which means there is a potential for data loss.
Method 2:
Step 1: Check if the issue occurs in Safe Mode.
Safe mode is a troubleshooting option for Windows that starts your computer in a limited state. Only the basic files and drivers necessary to run Windows are started.
Follow the link below to learn how to do so.
http://windows.microsoft.com/en-US/windows-8/windows-startup-settings-including-safe-mode
Step 2: If the issue doesn’t occur in Safe Mode, then perform Clean Boot.
Clean boot: To help troubleshoot error messages and other issues, you can start Windows by using a minimal set of drivers and startup programs. This kind of startup is known as a "clean boot." A clean boot helps eliminate software conflicts**.** Here is the link for your reference to perform clean boot.
http://support.microsoft.com/kb/929135
Note: Refer "How to reset the computer to start as usual after troubleshooting with clean boot"
under more information to reset the computer to start as normal after troubleshooting.
Hope this resolves the issue. If the issue persists, you can write to us and we will be glad to assist you further.