Please help me!

I recently just started up my Windows 8 HP Laptop, and when I tried to do my daily scan on Windows Defender it says: Windows cannot find 'C:\Program Files\Windows Defender\MSASCui.exe'. Make sure you typed the name correctly, and then try again.

Please give some advice on what to do. Do I have a virus? Do I need to update my computer? Am I just being a complete idiot and missing what I'm supposed to do? I'm just stumped, and I'm worried I'm going to get a virus.

Please respond to this, because I just don't know what to do.

(1)Do you have any other antivirus solutions installed?If so they can conflict ..... and cause such issues...

Remove them.. http://answers.microsoft.com/en-us/protect/wiki/mse-protect_start/list-of-anti-malware-product-removal-tools/2bcb53f7-7ab4-4ef9-ab3a-6aebfa322f75

(2)Do you use system optimizers/ registry cleaners? If so they can conflict ..... and cause such issues... 

http://www.edbott.com/weblog/2005/04/why-i-dont-use-registry-cleaners/

(3)Check this Checklist/FAQ

Windows Defender on Windows 8 - Introduction and Frequently Asked Questions

(4) Make sure you are not alredy infected... Use one scanner at a time

Download hitman pro 3.7 (shareware and can be activated for 30 days free)and have a full system scan..http://www.surfright.nl/en 

And/or
use malwarebyte have a full system scan http://www.malwarebytes.org/products/malwarebytes_free/

And/or use TDSS Killer have a full system scan..: http://www.bleepingcomputer.com/virus-removal/remove-tdss-tdl3-alureon-rootkit-using-tdsskiller

• Proposed as answer by Hetti Arachchige V Aravinda 2 hours 21 minutes ago