Restoring your Outlook 2007 dictionary additions is easy but you just need to make sure you can recover the data or you back the proper file on a regular basis. The additions to the Microsoft Outlook 2007 dictionary are added when you Spell Check an email and instead of correcting the spelling you click the “Add to Dictionary” button.
First you need to know the location of the file so use the below locations for either Windows XP or Windows Vista. The file name is CUSTOM.DIC in all caps.
Windows XP Location: C:\Documents and Settings\<user>\Application Data\Microsoft\UProof\CUSTOM.DIC
Windows Vista Location: C:\Users\<user>\AppData\Roaming\Microsoft\UProof\CUSTOM.DIC
So make sure you just back up the entire UProof directory if you are using a backup application like Jungle Disk. When you need to restore the file simply copy the backed up file into the proper directory shown above. You don’t need to worry about Outlook running as the CUSTOM.DIC file is only called during a Spell Check.