Create a new local profile. Open Windows Explorer. If it still exhibits the same behavior you can effectively rule out mapped drives.
We had this problem on Dell laptops with modular drives (CDR / Floppy are interchangeable). Turns out the BIOS has a setting that somehow affects when the OS sees that a drive has been removed and a new one is present. For example, a user removes her floppy drive and inserts the CDR. After she boots up and opens Explorer, there's a LONG wait as the OS still thinks the A: drive should be there.
The fix was to update the BIOS as well as change that setting for the modular drive. We don't have those machines anymore, and I'm sorry I can't recall the exact name of the setting.
Other things that can cause this behavior:
- bad/damaged media in any drive (CD, DVD, Floppy, etc)
- excessive mapped drives
- mapped drives over slow connections
I'm taking it this behavior occurs in Explorer as well as the Office apps you've listed?