Disconnected Admin Logon To Desktop And Settings Path

My Win 7 user account has a special character in its name. I wanted to install a particular piece of software that, for some reason, couldn't use a name with a special character as an install path. I decided to rename the user account folder. I thus created a new admin account, logged on with it, went to the folder with the username with a special character and changed the name. The next instruction I needed to follow was to make an adjustment in the registry, but windows wouldn't allow me to open the registry; it blocked me as measure of protection from unknown online files, apparently. I then decided to try accessing the registry from my original admin account, but when I logged on to it, Windows had factory-defaulted, and all my files had disappeared from the desktop and from within what few folders remained on the desktop.

I did a system restore. This did not restore the desktop files , though it did restore my Windows settings. I opened Firefox to access the internet to find out how to solve my issue, but Firefox too had defaulted. All my bookmarks and add-ons have gone, even when I log into my Firefox account.

When I go to C disk > Users, I can see the original admin user folder (not renamed), which contains the new defaulted desktop folder. I can also see the new (renamed original) user folder for my new changed name, and inside, the desktop folder contains all my original folders and files, intact.

So, because I did a system restore, I seem to have my original admin user folder name, but with the new defaulted desktop and settings. I also have what used to be that folder, but now with a changed name, and the original desktop contents, but I don't have a user account for this folder, so I can't log into it.

I can only log into the original named admin account, which now leads to the new default settings and desktop.

How can I link my newly named folder with all the original contents to a new admin account?

Win 7 Home Premium SP2