Hi PA Bear:
None of the basic diagnostics I've run [e.g., chkdsk /r, sfc /scannow, System Update Readiness Tool (MS CheckSUR), etc.] have found a problem with my Vista OS or Windows Update components. My system was checked by a malware removal specialist in Malwarebytes' Malware Removal Help forum (FRST, ESET Online, AdwCleaner, JRT, RKill, etc.) and there was no evidence of a malware/PUP infection. I have no issues with my IE9 or default Firefox browsers and as I've repeated many times in this thread, my only problem is that "Checking for updates..." has been hanging for several hours during Patch Tuesday updates since August 2015.
You've said you "very strongly disagree" with my observations without providing an alternate explanation and called me a "troll" in Laura1836's thread Windows Vista Update. You're entitled to your opinion but I won't be responding to any more of your questions until you tone down the rhetoric. I have no problem if anyone disagrees with something I've posted as long as they do so in a respectful manner.
32-bit Vista Home Premium SP2 * Firefox v46.0.1 * IE9 * NIS v21.7.0.11 * MBAM Premium v2.2.1
HP Pavilion dv6835ca, Intel Core2Duo T5550 @ 1.83 GHz, 3 GB RAM, NVIDIA GeForce 8400M GS