Yes!  Mozy runs in the background so that you can use your system while it it backing up your files. 

In some situations Mozy's backup may cause your system or network connection to slow such as:

• Large backup
• Low system memory (RAM)
• Low Disk Space
• Online gaming (depending on your upload speed from your ISP)
• Conflicting 3rd-party software

Note: Usually the largest backup will be your first, after which only new or updated files will have to be sent to the servers (process referred to as Incremental Backups); this means that after your first backup finishes you will see little effect on your system.  You can adjust the way that Mozy decides when to backup in the settings/preferences.

You can even use your system when Restoring files, however there are a couple of things to remember:

• If you create a file with the same name as one of the files that you are restoring you will lose one of them depending on your restore settings (overwrite/skip).
• Folders with the same name will merge together, however if you move or rename a folder mid-restore the files that haven't restored yet will not follow.  Either the folder will be recreated or the restore will fail.