Extenstion Failed Cannot Open File Extend.dat

So I'm certain this is posted here somewhere, but I can't spend the hours needed to find it...so sorry for probably repeating something. I just purchased a computer with Vista 64 bit, even though I had my reservations about the OS. I then migrated some data from my last laptop and installed my copy of Office 2007 Enterprise. I imported my personal folders into outlook, which seemed fine. I set up my email account and noticed that I could send emails from my outlook (using an internet email account from a work server) but not receive. I also started noticing this error when running outlook: "An extension failed to initialize. Cannot open file: extend.dat. The file may not exist, you may not have permission to open it or it may be open in another program..." I looked around the internet and tried to find a fix for this error. Most places said to find the file and rename it. I have searched every way possible and cannot find the file to rename it. I'm not sure if this is even related to why I cannot receive email.

In addition, when running outlook, I also periodically receive the error "Your AutoCorrect file, MSO1033.acl could not be saved. The file may be read only, or you may not have permission to modify the file." I also get this permission language at the bottom of the previous error message. Upon exiting outlook I get a similar error about not being able to save a file. It then opens a dialog box for me save the file as a macro enabled template...I receive basically the same errors (without the enable.dat error) when running Word. None of the other programs seem affected. This is supposed to be a work PC and if I cannot properly run word and outlook, it will prove quite pointless. I had no problems running this copy of Office on my last computer, which was running XP. I have installed all the windows and office updates, as far as I know.