iTunes upgrade - insufficient privileges

The message reads:

The installer has insufficient privileges to modify this file: C:\Users\Public\Desktop\iTunes.Ink.

Thank you so much. I appreciate your assistance. Unfortunately, after following the steps in the post, I still recieved the same error message. The only step that did not work in the process was the removal of the folder: C:\Program Files\Common Files\Apple. When I selected this folder and clicked "delete" I recieved a message saying the folder could not be deleted because it was either open or in use by another program. I could find nothing where either of these could be the correct. As a result, I am still without iTunes.

I appreciate everone's help with my problem. Here's where I am currently at. So far, I have uninstalled the Apple related programs and also was finally able to delete all the related files including the dll exensions. I continue to recieve the original error message saying, "The installer has insufficient privileges." I have even attempted to install older versions of iTunes to see if I can get one of them to install with the same results.

I've been several weeks now without iTunes to back up or update. Honestly, I have tried to follow everyone's suggestions step by step, but so far no success. I've read other threads concerning the same issue and followed thier suggested solutions. Let me just say, this is VERY frustrating. My son suggests the reason I'm having the problem is I am using a PC and should go Apple on everything, but I've never had this kind of problem with a PC or a related program. I'm not saying I couldn't though. It is starting to make me wonder if I should dump the Apple stuff and go all PC including my phone. I guess you can tell I'm frustrated.

Does anyone have any other suggestions I could try?