Copy the backup file to the MSSQL7 > BACKUP folder. Start Enterprise Manager, select your server from the Sql Server Group.
To restore database, right click onto the Databases folder icon and choose All Tasks > Restore Database. Type in the name of your database, and choose to restore from device. Click on select devices, Add and the à box to browse. Select your database file and ok, ok again, and ok once more. Under the options tab, click onto ôForce restore over existing database. Make sure that the Move to physical file name is listed as c:\whatever. Mine always comes up as d:\whatever.