Windows – Settings to rotate display by 90 degrees

You could take a look at the Flip This Chrome extension. It allows to rotate and flip any page (according to the description)

Microsoft KB article(http://support.microsoft.com/kb/950505)

1. Click Start, then click Run.
2. In the Open box, type explorer and then click OK.
3. Navigate to the Windows directory (e.g. a typical path may be C:\Windows) and locate regedit.exe.
4. Right-click on regedit.exe and select Run as. Uncheck "Protect my computer and data from unauthorized program activity" and click OK.
5. Using Regedit, locate and then click on the following registry key: HKEYCurrentUser\Software\Classes
6. On the left panel, right-click on the following registry subkey: '.exe'
7. Select Delete and then click OK.
8. On the left panel, right-click on the following registry subkey: 'secfile'
9. Select Delete and then click OK.
10. Close Registry Editor.

Also get an antivirus and scan and clean the PC.
MalwareBytes and ComboFix are good and free ones.