companyweb is downloading instead of displaying

[DrewGossage]

Whenever I try to access

http://companyweb

a Save As dialog box comes up instead of displaying the page in the web browser. If I manually type in

http://companyweb/default.apsx

it displays our main page with the default sharepoint theme, none of the internal links work, and all the documents wont open. The MS Word docs open but show up corrupted (little boxes at random parts of the page). I have tried to restore from last night's tape backup, but the same results occur.

Any ideas on what might have changed or places to look? I have scoured over IIS and the InetPub folder and found nothing out of place or misconfigured.