Windows update not working after installing windows 7 professional on a Dimension C521

The date and time must be correct.  You must have a live internet connection.

Then you download and run the update troubleshooter.

http://windows.microsoft.com/en-US/windows7/Open-the-Windows-Update-troubleshooter

Windows Update after operating system install,  I have checked date, time, location and have internet connection.  I had to open internet explorer and update to internet explorer 11, I have downloaded mse virus protection and run your link to update troubleshooter result below, no change to windows update. I updated from xp.  My bios version/ date dell Inc 1.0.3  02/10/2006.

The 2006 Dimension C521 was only validated with Windows XP/Vista. When you installed Windows 7, how did you activate it with Microsoft?

Lots of people (including me) having issues with Win 7 updates recently. Read this.

I activated from system properties with product key.

Ok. Good to know. A non-activated system over time would not be able to do updates. Try the fix by RoHe.

RoHe download took me to windows update standalone installer searching for windows updates, half an hour later internet explorer had to close.  I rebooted and downloaded service pack 2 from natakuc4 which downloaded and installed i rebooted and strangely i am still on service pack 1.  Is it possible to carry out a clean install of windows 7 professional  from microsoft and might this be an option

Moving this to the Microsoft operating system board since it is not a General Hardware issue.

Thanks i have tried to access post but cant find it

A little embarrasssing but I have just realised that I only have 1gb of ram installed on pc could this be my problem.

The 'Service Pack 2' is NOT an actual service pack, its a rollup or courtesy service pack.  If you install it and it works, Windows will not say its running service pack 2, but still service pack 1.  Everything from that point should be fine.  Microsoft doesn't want to make a service pack 2 because they would have to extend the life of Windows 7 and they are pushing people to Windows 10, which I wouldn't do as yet IMHO.  

Thank you beamermt79 interesting but this install did not change my situation with windows update and the only error that i am aware of is the fact that i have installed windows 7 to a pc with only 1gb of ram,  specifications for windows 7 are 2gb of ram,  could this be my problem.