May I know the version of mcafee back up & restore you are using ?
Also please try to attach an image of the error you receive as it would help us in proceeding further.
May I know whether you are trying to open data back up from within the security center or from the quick links ?
Also let me know what is the operating system of the computer ?
Are you trying to do a back up from a network drive ?
I'm opening Data Backup from within security center. The OS is Windows XP, Media Center Edition, Version 2002, SP 3, and the drive I'm trying to backup to is an external USB drive. I've done backups before to this drive too.