Windows 7 - Skype problem.

Hello everyone,
I'm not sure if my problem because of Skype program, or I have a virus, or maybe I need to reinstall windows, but anyway, when I want to sign in to skype it opens me a page with index folder! also lately the Windows media player is not working, and when I tried to restore my windows to a previous time, it didn't find any restore points!
I tried to fix my "C" drive with "Tune Up Utilities" but didn't work also.
if anyone can help me, I would be thankful!
I uploaded a print-screen after clicking the sign in button.. same window I have when I try to check the "sign me in when skype starts", "start skype when computer starts" and "create a new account".. please help :\
and thanks in advance.

> "Tune up utilities" may have indeed done more harm than good.

Current accepted wisdom with Win 7 is to NOT use a "cleaner."

If you ever think your Registry needs to be cleaned, repaired, boosted, tuned-up, cured, tweaked, fixed, or optimized it shouldn't.

In other words, injudicious use of "Registry cleaners" CAN cause problems.

> Suggest you do a SFC, Option 2.
You may need to run it at least three times to receive a good report at the end.
SFC /SCANNOW Command - System File Checker

> Please download the free version of Malwarebytes.
Update it immediately.
Do a full system scan
Let us know the results at the end.

Malwarebytes : Download free malware, virus and spyware tools to get your computer back in shape!

> Have you tried uninstalling & reinstalling Skype?