How do I redo System Restore properly?

So this is what happened:

I was using ccleaner to uninstall some software that I thought I didn't need. Apparently, I accidentally uninstalled one of the system files I believe. Now, when I rebooted it, there is no taskbar (just blue and the place where you have a clock is white and blank) and the desktop has no apps in it. Also, when I use alt+tab, the format looks entirely different. I remember the file I uninstalled was around 20 mbs. Afterwards, I tried using a system restore.

I have bitdefender, and as a result, it caused the system restore to fail. I decided to temporarily uninstall bitdefender (planning to uninstall it again later). However, when I tried to do system restore again, the icon had disappeared! (It says that there is no restore point) How do I redo the system restore?

You may try to do a Repair Install to try to get that system file back.

http://www.eightforums.com/tutorials/26095-repair-install-windows-8-a.html

You may also do sfc /scannow from the elevated command prompt. If unable to repair all corrupt system files you can run
Dism /Online /Cleanup-Image /RestoreHealth and do the sfc command again.

If there are no restore points they are gone. Failing all this, you may have to choice but to reinstall Windows. Back up your data first.