Thanks for the couple of questions that I got on my end of year post. Let's look at the first one:
"Many times after reinstalling Vista, I can't reliably install already downloaded *.cab updates (things like Ultimate Extras and Bitlocker repair tool etc) using pkgmgr. Sometimes, the packages "install" (appear in Programs & Features) but actual files are not installed (no games in program files) and shortcuts don't appear in Start menu. I have to uninstall and installing again makes them work *sometimes*. This never happens with MSU updates because they're maybe handled by WUSA.exe? The same issue also doesn't arise if I install Extras and cab updates from Windows Update. This happens on Vista SP2 (both 32-bit and 64-bit)."
There could be several reasons this could happen:
1. Because of package dependancies on the OS, you may hit a point where a portion of the update has been superseded by another update thats attempting to be installed. This should happen on tools like the Bitlocker update because they arent shipped in box on Vista, but other updates may fail because an update that was installed post clean install is actually newer than the one you are attempting to install.
2. In the case of the Bitlocker update, or other tools updates, they have service pack dependancies that must be met in order to properly install. Let's say you have downloaded and installed the Bitlocker update from when it was first realeased a couple of years ago. You flatten your machine but still have those bits sitting around and attempt to pkgmgr the files in and it fails. It's most likely failing because the OS you are now running is on a later service pack than what the package is expecting. This will cause it to fail.
3. This last reason might come off wrong, but the reality is that we dont really want you using pkgmgr unless you have to. WUSA and the was we package the standalone updates allow us to make sure that specific dependancies and applicabilities are checked when you attempt to install an update. We would prefer that you use that method if you can because we have tested those packages that way. Also, if a package is working using the WUSA method, then you might have syntax issues when you are installing the update via pkgmgr, but because pkgmgr lacks any great logging, it can be hard to pinpoint why its happening (this is resolved with DISM in Win7). The pkgmgr option is really meant for the creation of a unified image.
Hope that helps clear that up a little bit. If not, post some comments and I will clear them up.