This is a little late but I made this little guide on anyone who reinstalls Windows 7 and wants to download all the Windows updates and not have
to wait an hour or so to do so.

 

 

 

Microsoft released a Windows Update Client Update which is part of the July 2016 Update Rollup to fix the long hang at Windows Update scan.

 


To be able to install the update you first need to install the April 2015 servicing stack update for Windows 7 and Windows Server 2008 R2 update
(again, stop WU service before trying to install the MSU).

 

1. Download (April 2015 servicing stack update):
32bit: https://www.microsoft.com/en-us/download/details.aspx?id=46827
64bit: https://www.microsoft.com/en-us/download/details.aspx?id=46817

 

2. Stop Windows Update service before installing by going to start/Run "services.msc" and going down the list to Windows Updates, right click and
click stop.

 

3. Install the update.

 

4. Restart

 

This update contains some improvements to Windows Update Client in Windows 7 Service Pack 1 (SP1). This includes the following:
An optimization that addresses long scan time for updates that's reported on some computers.

 

5. Download Windows Update Client Update:
32bit: https://www.microsoft.com/en-us/download/details.aspx?id=53335
64bit: https://www.microsoft.com/en-us/download/details.aspx?id=53332

 

6. Stop Windows Update service before installing by going to start/Run "services.msc" and going down the list to Windows Updates, right click and
click stop.

 

7. Install the update.

 

8. Restart

 

9. Download Windows update KB3102810
32bit: https://www.microsoft.com/en-nz/download/details.aspx?id=49542
64bit: https://www.microsoft.com/en-nz/download/details.aspx?id=49540

 

10. Stop Windows Update service before installing by going to start/Run "services.msc" and going down the list to Windows Updates, right click and
click stop.

 

11. Install the update.

 

12. Restart

 

 

 

Your Windows updates should check and install much quicker now, if not, then sorry. :)

 


Source: http://superuser.com/questions/951960/windows-7-sp1-windows-update-stuck-checking-for-updates