All Application Installations In 64bit Error

I am having repeated problems with a new Toshiba Laptop that, regrettably, has Windows Vista Home Premium 64bit.:mad: The computer is so new that I am still in the process of installing all of my applications and tools. I finished installing Office 2007 and then came the problems. NOTHING would install. For example, I triied to install the 64-bit version of iTunes and it started, asked if I wanted to RUN it, and when I selected RUN, nothing happened. It ran for a few moments and then just stopped. I tried to run the 32 bit version and it went all the way to the point of telling me there was a 64-bit version and was I sure I wanted to install the 32 bit version. In other words, Vista was willing to install the 32 bit version but not the 64 bit. I then tried to install Snagit, and while installing Snagit, I got the

following error:

"*Internal Error 2908. {32C6FEA0-576F-4661-9304-82BB4BFF390C}*" and then

"*Internal Error 2908. {49190E7C-167E-4702-B628-4D69B80A8C69}*" Plus another 50 or 60 keys with the same error.

THEN, "*Error 1406. Could not write value RegOwner to key Products]81D19995889ABA541BFBA5EDE646DCF3InstallProperties*"

I tried to hit _Ignore__and then _Retry_, but they did not work. Have had to _ABORT_. After some research I tried to reinstall the Installer by renaming some old components and then reinstalling. I then tried to reinstall Windows Installer for Vista 64 v4.5, file name "*Windows6.0-KB942288-v2-x64.msu*". Despite the fact that this is supposed to be the right one for 64bit Vista, the RESULT: "The update does not apply to your system." I then followed the process to reset registry permissions. The first attempt used the subinacl, which I realize is for the 32-bit keys, but I found few options.