Can't Minimize Programs To Taskbar

I had to restart my computer after it finished a spyware scan. It restarted just fine, but I noticed a lot of things wrong once I logged on.
1)can't minimize programs to the taskbar. They won't show up if I try to minimize them, but I can access them by using alt+tab.
2)can't hide inactive windows, no circle with the arrows to click to minimize. I've tried right clicking on the taskbar and going to properties, but when i click hide inactive icons, and click apply nothing happens. Also when I click the customize button, the customize notification menu is empty.
3)I have no sound. I went to the control panel and checked on the sound and audio devices. I went through all of the tabs and they all said there was no device, but when i checked the hardware properties it said everything was working properly.
4)when I access the task manager and click on the processes tab, the user name column is empty. Usually there is either administrator or system.Other than these problems, everything else works fine. I recently installed something before my computer restarted and I uninstalled it and restarted it again and the same problem was there. if anybody knows what to do I would be extremely greatful.