I'm a college student and I need my computer

So I shut down my computer and installed a few updates; everything was working fine prior. Then. My friend and I decide to watch netflix in her room so I grab my HDMI cable and head to her room. When I hooked up my computer, I found out that no programs would open: Microsoft Office, iTunes, Flixter, Google Chrome, etc. Frustrated, I finally opt to do a system restore to a point of about a week ago. Everything was fine! Then, I boot up my computer again later (I'm running Windows 7 by the way) and I'm getting error messages from iTunes saying "The iTunes Library Extras.itdb file is locked, on a locked disk, or you do not have permission for this file." Also, Microsoft Word 2013 gives me an error saying: "Word could not create the work file. Check the temp environment variable." Not only that, Sky Drive always stops responding when I try to log in. Internet Explorer won't even open to my home page; it also won't let me even touch the settings in IE. Although Google Chrome works just fine (hooray for Google!) and I can pass through my Microsoft Word to actually create a document, this is really bothersome because I can't upload my notes, assignments, etc. To Sky Drive, which would allow me to practically study anywhere I have unexpected free time. In order to sync my iPhone, I actually have to right click my iTunes shortcut and click run as administer to even open iTunes. I don't think this is a virus or malware because I've ran malwarebytes, Symantec, Avast! And Microsoft Security Essentials, and they've found nothing. Some help would be greatly appreciated from a university student!

I would try an earlier Restore Point than the one that you have already tried, and do so in "Safe mode", as follows:

Upon starting the machine, keep pressing the "F8" function key (see the top row of your keyboard) until the "Advanced Boot Options" screen appears and there choose "Safe Mode".

In Safe mode, do:
Start/All Programs/Accessories/System Tools/
Right-click "System Restore"/
Choose "Run as administrator/
Click "Next":
It shows a list of dates and times.
Display more dates and times by ticking (checking) the box that says:
"Show more restore points."
Choose a "Restore Point" dated prior to the problems.

It sounds like somewhere along the way You either lost some of Your Admin privilege settings on the main UserID or part of the Usr profile settings themselves. You MAY also have a harddrive mechanical problem, but I'd personally start by dealing with fixing the access issues with the user ID before running ANY hardware scans or defraggers, etc.

next time You start the system go to User accounts and remove Your login password, wait a few minutes for it to update all secured files properly, and reboot. Let it start completely, including all programs, taskbar/quicklaunch items, and software updaters in the background.

Run a disk check with repair bad sectors options, then a defrag… This will probably take a LONG time, start it overnight and go to bed.

Then do a reboot, and reset Your password on the Admin account/ID. Reboot one last time and You should be able to access everything properly.

BTW - If You have All those antivirus/spyware programs installed at the same time… Your performance and data safety are at HUGE risks… You should NEVER have more than one antivirus and one anti-spyware program on any system together. Pick one of each and remove the rest. It has to do with one prgram locking out the security definition files of another program, which that program sees as a security attack, and locks out the first program, and then we get corrupted files in the User accounts due to "lockdown modes"…