I have a report that would export to excel in 2000 version.
Now that I have updated, I can no longer export to excel. The option is not highlighted and is not available.
Any reason why?

Since you updated, you probably broke the reference to the Excel object library. See if you are missing any references.

Search this forum for ways to re-assert broken references. Topic is "references" and "missing references"

After searching the forums,
I have tried checking and unchecking many different references.
None are labeled missing.

Visual basic for app
microsoft access 12.0 object library
ole automation
microsoft office 12.0 access database engine object

is there any Im missing?

My excel export option is greyed out on my ribbon and is not available

After searching this issue for hours i have found some evidence that you cannot export reports to the Excel format in Access 2007. Microsoft has disabled this functionality.

here is the link:
http://support.microsoft.com/kb/934833

You can still do it if you use the Excel COM Object model though.