Important updates failing, Windows acting sluggish now :(

Windows is failing to update the following:

Security Update for Microsoft .NET Framework 3.5.1 on Windows 7 and Windows Server 2008 R2 SP1 for x64-based Systems (KB2742599)

Security Update for Windows 7 for x64-based Systems (KB2757638)

Update for Windows 7 for x64-based Systems (KB2726535)

There is also these optional updates:

Bing Desktop v1.1

Definition Update for Microsoft Security Essentials - KB2310138 (Definition 1.143.190.0)

Update for Windows 7 for x64-based Systems (KB2574819)

Update for Windows 7 for x64-based Systems (KB2592687)

Update for Windows 7 for x64-based Systems (KB2709981)

So yeah, Windows is acting sluggish and clearly wants these updates but won't give it to me. Troubling shooting ideas?

Try clicking Start button and in the search box type "Services" and hit enter, in the box that appears click Services and find Windows Update, right click and hit Stop(leaving the Services window open).

Now go to C:\Windows\SoftwareDistribution\DataStore and deleting all files apart from the log folder and any files ending with .log (but really it's not harmful if you do so don't worry), then close the window and back on the Services window right click Windows Update and Start.

Then try to update again. It might say that you've never updated with a red X but don't worry.

Got the optional updates installed by just going through them individually (except bing which is stupid).

I used your trick and got two of the important updates installed. Progress. There is still one giving me trouble:

Security Update for Windows 7 for x64-based Systems (KB2757638)

I tried to repeat your trick for this last one but it didn't work.

Well it worked for me, as far as getting it updating again. Wonder what the problem was to begin with?