What is the name of the file or file type where the contacts are kept in outlook express ver 6.

Use the operating system's search function to find files with "*.wab" in the file name. Make sure the search function is set to include files in system and hidden folders. Be prepared for there to be separate files for each Windows XP log in account.

Should be in the "\Documents and Settings\Account name\Application Data\Microsoft\Address Book" folder. Substitute your log in name for the "Account name"

Purpose is similar enough to use the information found in Microsoft Knowledgebase Article ID: 313055

"OLEXP: Mail Folders, Address Book, and E-mail Messages Are Missing After You Upgrade to Microsoft Windows XP"
OLEXP: Mail Folders, Address Book, and E-mail Messages Are Missing After You Upgrade to Microsoft Windows XP