|Generally the product keys are not written to the installation disks. The disks contain a formula to determine if the key you enter is valid. That way they can make all the disks the same.|
If the software is already installed on a computer you can sometimes find the key with diagnostic software like Belarc Advisor. It goes into your registry to find the keys.
I don't know why your keys are of different lengths. Is it possible one is a product ID rather than a product key? The key comes with the disk. The ID is created when you install it on your computer.
Sometimes using google and the correct search terms you can find lists of product keys for various OS's and software. But if the software needs to be registered with MS, the keys you find on the internet aren't much good as they've already been used.
Are you sure Works 2000 will run with windows 95?
Real men don't use AntiVirus; they just reformat