While waiting for noknojon to return let's get some feedback and an idea what we're working with.
I assume you have Windows 7 due to where you posted this.
Everytime I reboot my computer I get prompted to update Java, Firefox, virus protection, etc...
What prompts you?
Windows action centre would prompt if your AV isn't up to date or had issues but wouldn't care about the rest you noted.
A website would prompt you for Java if yours isn't using the version it wants.
Firefox looks after itself and should be updated by going to "Help" and "About", then look for "check for update".Note:
Nothing is stopping you from going and downloading the items noted above and saving them to your downloads and then installing them manually. In fact this might show you what is giving you a problem. Why not DL the latest version of Firefox, 10.0.2 I think, and then install it manually over top of your existing version? (Java can be a pain and leave older versions behind so leave it for now.)
Do basic system checks such as check disk "chkdsk /f". See how much space is left on the hard drive either from the command prompt or properties of the "C:" drive.
Failing that you should at least be able to give better information on what you have done and what the results are.