ColdCoates90- Actually it can only recognize 3 GB of RAM. If your system is picking up 3.3 then your video card must have .3 GB or RAM. It's not Vista's fault - in other words: it's not Microsoft's fault - that the 32-bit version of Vista doesn't recognize past 3 GB of RAM. It is a fate for all 32-bit operating systems. The 32-bit architecture cannot map past 3 GB.
I agree with you that Vista is a very good OS (when the computer can run it well). I suggest it for the most part to everybody, but there are some people where I will say to get XP.
I just want to clear up one thing I dont agree with you about. A 32-bit OS can map past 3 GB of RAM. While I agree with you that it is not an issue with Vista, I belive the reasoning is false. The average 32-bit OS will see between 3 and 3.5 GB of ram. See the techincal stuff below.
As for the upgrade...
A clean install is always reccomended. It prevents a lot of issues from even starting to happen. Personally, I would back up all of your documents, reformat and install Vista.
That does mean that you will need to reinstall all of your programs again so you would need to have the install media and license/ product key if needed.
A clean install generally will also make your computer more responsive if you have a lot of unused programs on the computer. this is because a lot of programs like to start a launcher program and or service when the computer starts. Not to mention just clutter the hard drive.
One of the issues that is popping into my head right now.. is DRM issues with music that you downloaded, if any. If you downloaded music from any source that had DRM that license is attached to that install of Windows, upgrading (without reformat) should prevent the issue.
You can skip the stuff below unless you want to learn about memory addressing.
----------------- Technical stuff ------------------
A 32-bit OS can map 4 GB of total memory addressing (IRQ range). Pretty much any piece of hardware on your computer does take some of that memory addressing, just usually very little. RAM gets addressed last. So sometimes if you too more RAM than get be addressed, you cannot use the unaddressed RAM (it doesn't see it).
Graphics cards are some of the main culprits of taking away memory addresses, since the RAM in the graphics card will use its size in addresses. A graphics card will never add its ram to the amount of system ram.
This is why we see some systems that have a 1 GB graphics card, and tons of addon cards, see only 2.5 GB of RAM when there is 4 GB installed.
And if you were to swap out that the graphics card with a 512 MB card, or even smaller, that system would see more RAM.