it's a major flaw with the outdated Windows Update Agent/Client application for Windows Vista having problems checking for 250+ worth of post-SP2 updates for Windows Vista, phansen. The last version of the WUA for Vista is v7.6.7600.256 dated 6/2/2012 and lately it takes many hours for WU to check for updates under Vista.
Microsoft had permanently fixed this problem for Windows 7 users by updating the Windows Update Client app to v7.6.7601.23453 for Windows 7 SP1 starting with the KB3161608 June 2016 update rollup and with the KB3172605 July 2016 update rollup. So far Microsoft has not issued a long-term fix for Windows Vista.
For those Vista SP2 (and some Win7 SP1) users still having problems with Windows Update taking so long in checking for updates, see this page for the solutions:
http://wu.krelay.de/en/
anyways, I've upgraded any of some old PCs I found using Vista to Win7 since Microsoft will end all support for Vista on April 11, 2017.
Bron
