I've had years of experience with PC's, every OS for them to date. I have been surprised by the difficulties encountered with Vista. Many, but not all, have to do with its "security" scheme. It has been sufficient to encourage me and some of my buddies to begin planning on refurbishing some of our older machines and trying some Linux distribution. The theory is that it takes less resources, runs faster and the device drivers are there for older machines.
Here are some clues for you to research..use HELP...and the web to understand the details... too much to include here.
User Account Feature..can turn off/on, requires a reboot, learn what it does, when to use it and when not to.
make sure you are an ADMINISTRATOR. Make sure there are more than one ADMINISTRATOR users... else if you mess up a password you will have trouble
use right click and RUN AS ADMINISTRATOR (even for ADMINISTRATOR users)
there is a
TRUE administrator account that is HIDDEN on most distributions for home use..Home Premium, for example...requires knowledge of command line interface..but, this is a TRUE back door to ADMINISTRATOR privileges, without passwords!
The fancy ASTRO interface is a huge CPU/GPU hog..about 8% CPU for its one HIGH PRIORITY process, I dropped it and went with a different one.
Learn about JUNCTIONS
I use AVAST for antivirus, COMODO for firewall, COPERNIC basic and COPERNIC DESKTOP SEARCH.
That said, you will STILL be extremely frustrated with Vista if you are used to being truly in control of your computer. BUT, these hints will give you lots to study...how you use the various features, etc, depends on your situation and needs.
Best wishes!