windows 7 - Can't log in normally, have desktop and user profile issues in Safe Mode

For some reason my computer has some problem(s) that I don't know the origin of, nor how to solve them.

I've had these problems for three days and have tried to fix them but to no avail.

Here are the issues:

When I try to log in on my computer I get a message that says:

The group policy client service failed the logon, Access denied.

Then it logs off and returns to the profile selection screen.

After that I tried to log in via "Safe mode" and it work without getting the message. However here comes my next problem (these problems are only in Safe Mode since I can't log in normally):

When I log in via Safe mode, my desktop icons are gone and my background is black. Also some of my programs in my Start Menu are gone.

On my "computer" (windows+E or via the Start Menu) some folders on the left panel are gone. When I right click and click on " show all folders" nothing happens:

Things that I've tried:

1. 
   

   Chkdsk (doesn't find any problems)

   
   


2. 
   

   SFC/scannow (found some corrupted files, don't know what to do after that - it only said that some files couldn't be repaired and that the repair will take place after rebooting. I did restart my computer but the problem is still there)

   
   


3. 
   

   System restore (didn't help at all)

   
   

My other problem is (also in Safe Mode):

In my profile: c:/users/eric (personal profile) I only have the following folders:

Appdata
Contacts
Desktop
ntuser

(I can't find my documents, videos, pictures etc)

Here is a screenshot of it:

What is causing this problem? Is it the user profile or something else?

I will not try to fix my computer now, in case I do something wrong and all my files are deleted (videos, pictures, documents and files that were on my desktop). Does anyone have a safe solution?