Reinstalling IE isn't very difficult, nor very risky. But there are alternatives.

Repairing IE is even more easy and even less risky: Control Panel>Add/Remove Software; search Microsoft Internet Explorer, click on Add/Remove, and choose Repair. This certainly is worth the try.

Thereafter you could try downloading Mozilla (full Mozilla or Mozilla Firefox) as an alternative browser. It won't harm IE, so nothing lost if you're not happy with it. If Mozilla works, the choice is yours: either continue with these browser or uninstall/reinstall IE.

Hope this helps.