Sorry, but I don't have a clue what it is you have done to this machine.
We need to clarify some terminology so that we're all speaking the same language and possibly allow us to assist you.
Download: to transfer data from the internet to your computer. This could be a document, a video, a piece of software... Practically anything.
Install: this is what is done with software so that it will work on your computer - either from a disc or after you have downloaded it.
As it relates to software:
Update: these are typically free - you have an existing piece of software on your computer for which the developer has issued an update to the current version of their software - typically for big fixes, incompatability issues, etc.; although they can include new features. These are almost always downloaded from the internet and then installed. Ex. You have Snow Leopard (10.6.1) on your computer and Apple puts out an update to 10.6.2 which you download and install.
Upgrade: these typically require payment - you have an existing version of a piece of software on your computer and the developer has put out a new version, which you would then purchase, download or get the disc and then install. Ex. You have Tiger (10.4) or Leopard (10.5) on your computer and you purchase Snow Leopard (10.6), get the disc and install it.
Let's start at the beginning:
What Mac do you have - is it new to you or have you had it for a while?
What all discs do you have?
What version of OS X was on it before you did whatever you did?
Or is this a new hard drive?
What did you do?