Unable to open Notepad,Task Manager ,Regedit

[ajaxx195]

Today Suddenly I found notepad ,Registry and Task manager is not working.
I scan for virus using Mcafee antivirus but did not found any anything.My cousin brother was using my computer yesterday may he bought some virus in his pendrive.
When I open notepad i get this error " windows cannot access the specified device,path or file.You may not have the appropriate permission to access the item ".
I tried following four solution found regarding this error but none of this work.
1> sfc /scannow command (3 times)
2> Removed antivirus
3> System Restore
4> Permission for opening a file

However I can open notepad in safe mode .

Is there any other solution except Re-Installing Windows again.

Please Help me !

 

[Yard Dog]

Hello.. run malwarebytes . : http://www.sevenforums.com/tutorials/338716-malwarebytes-anti-malware-free.html

 

[Ztruker]

Try this: How to troubleshoot a problem by performing a clean boot in Windows Vista or in Windows 7

 

[ajaxx195]

Thank you everybody ......

I scan with MalwareBytes and it removed all virus and now everything is allright .

 

[Yard Dog]

Great . Now run this to make sure all files are intact : http://www.sevenforums.com/tutorials/1538-sfc-scannow-command-system-file-checker.html