I've been having this issue with anything Fallout 3/Fallout related lately, this includes mods from Nexus, and other sites.

Every time I try to install a mod/program for fallout, it never ends up getting installed due to a error I get when trying to extract the mod/program to the fallout folder.
The error i get says something along the lines of "Cannot create folder (path)", or something like that. I've made sure I'm running administration on the desktop. Strange thing also about my
issue is I can't seem to extract the mod/program to any folder, yes I've tried.

My temporary solution around this issue so far is I have to download the mod/program on a different computer, then put it in a Flash Drive and get it on this computer.
I'm happy with what mods I have now, yet today I wanted to download G.E.C.K to build things since I learned how to make stuff with the Fallout 3 G.E.C.K on my Dell.
The Dell doesn't have the same issue, I'm thinking its because the Dell uses Windows XP and this Built computer uses Window 7 causing Extraction issues.

I've managed to download G.E.C.K into my Documents but I can't move it for some odd reason, and i can't run it because it needs the appropriate .dll files. I've tried some other programs to extract the files, like ExtractNow and Winzip, but it draws me back to the same issue. I'm actually thinking it's a Administration option that can be changed or something. It isn't a virus, the computer is clean.
ExtractNow error: Unable to create output file.
Winrar error: Cannot create folder (path)
Winzip error: Unable to create folder (path)

I'm up for any suggestions.

It really sounds like a UAC issue. A program (Winzip, WinRAR, etc.) is trying to write a file to your computer but Win 7 won't allow it. One of the ways around this is don't install NV or FO3 to the default "Programs" folder on the C drive. I vaguely remember this being somewhat of a workaround. I always put games in a games folder on my D drive. Do some searching on Win 7 and UAC and see how to disable or limits it's control. Sorry, I don't remember off the top of my head.

Here are things I would check:

First, I think you should right click on your archival extractor program, go into its properties and look for any unusual flags on it. When you download programs they are often limited, if you see any kind of "always ask" or limited permissions options make sure they are not checked. I would also go to the "compatibility" tab and make sure that you have enabled "Run as Administrator".

Second, write down the exact error message you are getting, and try searching (leaving out anything specific to the archive or mod you are trying to install). If you someone else had the same problem you might be able to find how they resolved it. (But you should probably avoid sites without any google cache or useless sites like experts-exchange which just post the question and want you to pay to see if other people's answers were worthwhile.)

You could also try unlocking the permissions on the downloaded data (go into properties...) and see if that helps.

You could also try (and this would be a total shot in the dark, but might work?) logging in on a Non-Administrator account. If I recall correctly, windows 7 tries to arrange things so people do not use the administrator account and it may be that being a regular user and escalating to administrator when you need that works better for you.