Ok and this is right from MSDM Microsoft
How to obtain and install Windows 7 SP2
Since the release of Windows 7 back in 2009, hundreds of updates have been issued for the aging OS, and anyone who has done a clean install of Windows 7 knows how painful the updating process can be.
Officially, Microsoft only released a single service pack for Windows 7 - Service Pack 1 was released to the public on February 22, 2011. However, despite promising that Windows 7 would only have one service pack, Microsoft decided to release a "convenience rollup" for Windows 7 in May 2016. This single package combines all previously released updates from the release of SP1 to April 2016. So even though Microsoft isn't calling this a service pack, for all intents and purposes, it serves as one.
This article will show you how to install the convenience update (SP2 for Windows 7).
1. Prerequistes
Before installing the convenience update, make sure:
You are running Windows 7 SP1
You have at least 5 GB of free space available on your system disk
You have installed KB3020369 (download links below)
x64Bit:
https://www.microsoft.com/en-us/download/details.aspx?id=46817
x32Bit:
https://www.microsoft.com/en-us/download/details.aspx?id=46827
2. Download (SP2 for Windows 7)
Once the prerequisites are met, you can download the convenience update (SP2 for Windows 7) from the links below.
x64Bit:
http://download.windowsupdate.com/d/msdownload/update/software/updt/2016/05/windows6.1-kb3125574-v4-x64_2dafb1d203c8964239af3048b5dd4b1264cd93b9.msu
x32Bit:
http://download.windowsupdate.com/d/msdownload/update/software/updt/2016/05/windows6.1-kb3125574-v4-x86_ba1ff5537312561795cc04db0b02fbb0a74b2cbd.msu