I originally was failing 14 updates with 800b0100 and one other error code (forgot which). I went with manually installing them, and it took it down to 5 updates fail to install with only error code 800b0100.
I had some unstable RAM settings when first setting up the computer, where I think an update or so was occuring and the system crashing. Pretty sure only during the download process though.
Anyways, I've done everything on this that I can find.
SFC Scannow, System Update Readiness Tool, Reset content of catroot2, Remove any incorrect registry (none of the stuff they say to delete was even in there),
The only step that did not go 100% smoothly was "Register the Windows Update Files":
REGSVR32 WUPS2.DLL /S
REGSVR32 WUPS.DLL /S
REGSVR32 WUAUENG.DLL /S
REGSVR32 WUAPI.DLL /S
REGSVR32 WUCLTUX.DLL /S
REGSVR32 WUWEBV.DLL /S
REGSVR32 JSCRIPT.DLL /S
REGSVR32 MSXML3.DLL /S
On the bolded ones, I get:
This file does not have a program associated with it for performing this action. Please install a program or, if one is laready installed, create an assocation in the Default Programs control panel.
the Rename Pending.xml (there is no pending.xml file, cmd says cant find it, etc).
Turned off firewall and AV (WSE), renamed software distribution folder, Clear BITS queue, ran update 958056 (the tool that takes forever), ran chkdsk, ran disk cleaner.
Also, every once in a while, when trying to "Try Again" on the updates, it'll say "Windows update success! Updates unnecessary' or something like that. Then I hit check for updates, and those updates become necessary once again, and, all those language packs and remote desktop optional updates that I hid, become unhidden again.