TigerCat: Are you able to open IE up at all? If so, open it.. then click on "TOOLS", when the drop down menu appears click "INTERNET OPTIONS" another box comes up. There are tabs along the top. Click on the "PROGRAMS" tab. About 2/3 rds down is a section "DEFAULT WEB BROWSER" if the button to the right of it says "MAKE DEFAULT" and is bold, click on it. Then select "APPLY" then "OK". Hopefully that will fix it.
What you are doing there is allowing IE to be your default browser. Since you are using two browsers like I do. One has to be default, and since you run several other things with your IE browser it needs to stay as your default browser.