Computer Problem? Cant do a few things...?

So, I tried looking around and I cant find any answers on the internet about this, obviously I cannot be the only person having this problem. I noticed a few people having similar problems but no one answered them correctly for my situation.

I am running Windows 7 and I download quite a bit, until recently I could always download a file and set the download location to my desktop. This would allow me to find it much easier than having to find it in my download folder. My problem is this, now I cannot do that. Every time I try it says I lack said permission, yet I am the ONLY admin on my computer, everyone else who is on my computer is set to Standard.

I just now, tried moving a few new chapters of a manga into my "Manga" folder, which is on my desktop. But, I cannot move said files into it... Because I lack the permissions needed. How can I fix this? I fixed it once but I don't remember how.. I've cleaned my computer, scanned for Malware, scanned for everything else. It's clean and everything, just cant mess with my desktop... I can move files FROM my desktop, create new folders.. But I cannot rename the folder without approving it... Nor can I delete it without approving it.. Like.. *click delete* ... "Would you like to delete the folder" <-- This is fine, this is normal. *clicks yes*... THEN I have to accept it again as an admin.

I'd like to know how to remove the "You need Administrative Privileges" crap because it wasn't always like this. And I'd like to learn how to fix the whole.. not able to put things from other locations onto my desktop because that wasn't like that till a month or so ago.. Not even that long to be honest.

Thanks