Okay, hereby: welcome to UAC! That is not some obscure place for people with PC trouble, it's in fact a security mechanism which WinVista uses. That explains why you are asked for "Admin approval" when you try to (un)install things.

First question: do you own your PC?
If yes:
-Do you actually know/remember what type of account you created, the one you use to log on to your machine?
-What does the dialog which prompts for "Admin approval" look like? Does it feature a button called "Continue" (and another one called "Cancel") ? If so, try clicking "Continue"; if it prompts for a password, type the one you use for logging on to your machine. If that works, you now know that the account you use to log on to your machine is in fact an administrator account.

If no:
-You likely do not have an administrator account, ask the one who does own the PC if you are allowed to install things. If you are, try the stuff under "what does it look like?".