How to show backup or restore progress to user in a progressbar?

You can show backup or restore progress to user in a progress bar if you had installed 

sp_who2k5 

into your master database. You have to run the below command:

sp_who2k5 1, 1

The result will include all active transaction. Search the backup in the requestCommand field. The aptly named percentComplete field will give you the progress of the backup.