Microsoft Security Essentials won't update

[audaciousgoat]

I'm running a 64bit version of Windows 7 on a computer that's a few years old. I recently installed malwarebytes, and found a few trojans and a good bit of adware. Aside from that, my computer is very clean. I quarantined the viruses, but just now my computer has been acting absurdly laggy, taking about 10 seconds to allow me to type anything into Firefox. I tried updating microsoft security essentials, which hasn't been able to update since November of 2013, and I keep getting the error message 0x80070002, I tried installing a new version of it completely, but it gives me the error message you see in the computer. Any help or assistance with this would be greatly appreciated.

 

[lantrich]

Follow the instructions on this webpage.

http://www.faq800.com/article/error-code-0x80070002/45

 

[junkeymonkey]

try to run this fix it thing and retry --

http://windows.microsoft.com/en-us/windows/troubleshoot-problems-installing-updates#1TC=windows-7

then I would try to uninstall it and go back to Microsoft and reinstall it

http://www.microsoft.com/en-us/download/details.aspx?id=5201

 

[audaciousgoat]

try to run this fix it thing and retry --

http://windows.microsoft.com/en-us/windows/troubleshoot-problems-installing-updates#1TC=windows-7

then I would try to uninstall it and go back to Microsoft and reinstall it

http://www.microsoft.com/en-us/download/details.aspx?id=5201

I ran microsoftfixit, and it didn't give me results, if it was supposed to. It still won't let me update Microsoft Security Essentials however, and I'm getting an error message I was getting before, I forgot to mention it. Code 80070643, which it classifies as an unknown error.
When I tried uninstalling security essentials, it tells me it can't find some file like ess.msi. It gives me the error code 0x8007064

 

[junkeymonkey]

0x80070002
http://support.microsoft.com/kb/979281

Code 80070643

http://windows.microsoft.com/en-us/windows/windows-update-error-80070643#1TC=windows-7

http://support.microsoft.com/kb/976982

 

[junkeymonkey]

0x8007064c-- note the ''C'' at the end

http://support.microsoft.com/kb/958055

 

[junkeymonkey]

that first link gives a link to this to try ??

http://windows.microsoft.com/en-US/windows7/What-is-the-System-Update-Readiness-Tool