Windows 7 won't update

[mjmjpfaff]

my 64bit windows 7 home premium will not update.
it says in the action center turn on updates, so i turn automatic updates on in the control panel. Even though i just turned it on, the action center still says it is off, and when i manually check for updates via the check for updates feature, it says it cannot check because the service is turned off. I tried the microsoft fixit tool, and it didn't do anything.
My last resort would be to buy an external hard drive, backup windows and reinstall it again.
-thanks

EDIT: I forgot to include that microsoft security essentials will not turn on real time protection

 

[mubin]

So you are sure you didnt turn off any windows service? I am thinking of virus. My 64 bit windows never had a issue with update until a virus damage a key file and a important win7 update is not installing for missing file.

Scan with anti-virus and recover missing file if there is any.

 

[mjmjpfaff]

yes and also mse continues to find a cutwail trojan on my computer. it removes it, a few days later it is back. should i back it up and reinstall???

 

[mubin]

Then there is one. If you cant remove trojan from your system, backup and reinstall. But try to remove it first from safe mode scan. You have to install all previous update again if you reinstall windows. Its boring to me, so i just hide that little update.