Claire,
I've just went through this not too long ago, and hopefully my
experience could help.
If you could copy both of your data files (.mdf and .ldf) into the
"Business Contact Manager" folder under your personal profile:

"C:\Documents and Settings\<YOUR_USER_ACCOUNT_NAME>\Local
Settings\Application Data\Microsoft\Business Contact Manager"

Replace the <YOUR_USER_ACCOUNT_NAME> with your Windows user account..

After copying those data files in place, try finding the database
through Outlook's Data File Management (in Outlook 2007, under the File
menu)

Hope that helps,
Sun