I see that the patches KB3145739 and KB3153199, which solved it for many, were already installed in the previous updates.
If the initial "Checking for updates..." phase of your Windows Updates run for long periods of time without throwing an error message, this is a common problem that currently affects many Vista users. On my 32-bit Vista system, I would see constant consumption of ~ 50% of my CPU by the the svchost.exe process (i.e., complete saturation of one of my dual cores) during the "Checking for updates.." phase of my Patch Tuesday updates. Process Explorer showed that all this CPU was being consumed by Windows Update service (wuauserv) and more specifically by a thread for the Windows Update Agent (wuaueng.dll). My problem started in Aug 2015 - one month after the official release of Win 10 - and I would sometimes wait 5 or 6 hours before "Checking for updates..." reported that updates were available for download. See Kayla77's thread Processes in Task Manager During Updates for screenshots of CPU consumption on my system during one of these "Checking for updates..." hangs.
I've posted a possible solution to these "Checking for updates..." hangs in m#l's thread Updates not working, it has been searching for updates for hours in the MS Answers forum. These step-by-step instructions are based on the workaround posted on Dalai's webpage at http://wu.krelay.de/en/ and require users to pre-install the Windows kernel-mode driver (Win32K.sys) updates listed on Dalai's webpage if any are missing from your system. I see you found magicshaw's thread Help Update Problems... in this forum so I've posted a reply in post # 21 of that thread to address your specific concerns.
Note that Microsoft usually releases new updates for their Windows kernel-mode driver (Win32K.sys) each month that replace older updates, so Dalai updates his list of required updates at http://wu.krelay.de/en/ every Patch Tuesday on the second Tuesday of the month. You have to check Dalai's webpage each Patch Tuesday to see if there's a new Win32K.sys update released that has to be pre-installed before running Windows Update or your "Checking for updates..." hangs will just return the next month.
32-bit Vista Home Premium SP2 * Firefox v47.0.1 * NIS v188.8.131.52 * MBAM Premium v2.2.1
Edited by lmacri, 15 July 2016 - 01:56 PM.