I re-installed windows 7 on my home computer. After installing I was playing games fine and after one restart it slows everything down incredibly I can barely use Google let alone games... Please help...

Have you activated it, applied all patches or made any other changes?

I think you should doing a clean boot on your computer.

Follow these steps to perform a clean boot.
Step 1: Start the System Configuration Utility
Click Start
Start button
, type msconfig in the Start Search box, and then press ENTER.

User Account Control permission
If you are prompted for an administrator password or for a confirmation, type the password, or provide confirmation.


Step 2: Configure Selective Startup options

In the System Configuration Utility dialog box, click Selective Startup on the General tab.
Click to clear the Load Startup Items check box.
Note The Use Original Boot.ini check box is unavailable.
Click the Services tab.
Click to select the Hide All Microsoft Services check box.
Click Disable All, and then click OK.
When you are prompted, click Restart.

If this doesn't work please let me know so that we can get further steps.