Hyperlinks suddenly not working

All of a sudden hyperlinks from any package on my computer has stopped working.  It might coincide with me removing the Dell Protective Workspace, but I cannot be sure.  They hyperlinks work fine when I online.  I found that the htm and html extensions were associated with Opera, which was strange since I use Firefox.  I set them to work with IE.  Still no joy.  My I working with Windows 7.