"Windows cannot access..."Windows 7

:major
I believe I've searched High and Low for the answer and have came up short every time. I'm obviously just missing something.

My buddy brought me his computer saying he's "locked" out of everything. Receiving the error message:
"Windows cannot access the specified device, path, or file. You may not have the appropriate permission to access the item."

I enjoy finding and fixing problems on my own, so posting is a last resort, so here I am.

I've read about Malware, rogue spyware, HijackThis...read about hitting "Unlock" and adjusting permissions. First of all I CAN access everything on his computer, I just have to right click and "Run as Admin." Obviously not a practical way to access apps. Second, I can adjust permissions of individual programs, but doing so would take ALL day and then some, again NOT practical and not actually a fix in my eye's. When I try to adjust the permission settings at his C: in My Computer, I fall short with an error of: "Access denied" on multiple portions, to include primary folders such as "Programs files (x86)" and "Program Files".

He said what started the issue was him switching Anti-Virus/Spyware programs. He had "win 7 Anti-Spyware". He told me he uninstalled it and then proceeded to install his McAfee Anti-Virus. Then, later on he said he doesn't "know" if it installed all the way. But, when I turned on his computer, McAfee was finishing a initial system scan. I didn't find any thing left of the win7, and I also uninstalled the McAfee to ensure there were no permission issues with it. Neither worked.

Now I'm assuming it's a registry problem, although I have NO CLUE. If anyone could give me a lead or even an answer, I would be very appreciative! Thank you.

BTW this is an Acer Aspire running Windows 7. Don't think it matters much, but has 3GB RAM, 1.86GHz Intel proc. and Intel HD Graphics

Addition:
I ran "CMD", obviously "Run as Admin" and was able to "mkdir" and "del", but trying to access sysdm.cpl fell short with the same error.

 

tried to run ccc cleaner or another registry repair tool??

 

Yes, Ran CCleaner, there were registry errors, not to my surprise, but did not fix the problem.

 

Adding to: I just created another Admin account and that one is having NO issues access anything. Made me smile a little, gonna sleep on this one, thinking it's going to take a minute to figure out what he did with the permission settings.

 

Please help I am having the same issue on Win 7.

I have run McAfee Virus Check and everything in the Malware guide to no avail. The only way I can run anything is if I disable User Access Control or I right click and select run as admin.

I am thinking something has effected my registry - the only thing I can think of is that I recently tried to install a USB sound card but I can not understand how this would effect the permissions.

I have also tried restoring from a previously good state but this didn't work either.

Has anyone solved this problem? Do I have malware or a virus?

 

So I think i fixed the problem.

I created another admin account. I then went into the new admin account changed my old account to a standard user and then restarted the computer.

I logged into my old account (now standard) then logged out.

I then went back into the new admin account changed my old profile back to admin rebooted and logged into my old profile and hey presto all my permissions were back.

Please give it a try and see if it works.

 

I actually just ended up making a new Admin account and transferring everything that was on the other one to the new one and deleted the old one, basic but it worked. What you did was a good I idea, def. didn't think of it, thanks. If I ever run across that prob. again I'll give your technique a try first!!