Some phones it may be possable if the phone had certain apps on it but if all is lost and it didnt have a recovery app then no, its not undo-able, once the phone starts fresh, all the old data eventually gets written over by the phone, most phones have to have an app installed to recover the lost data, such as android, you can dowbload data back up apps to restore your phone, however, most phones when doing a hard reset will not delete any data from the memory card ( micro SDHC or SD) some times phones leave backup data on these cards in case something is lost, usually pictures and music are on the memory card and not the phone so those items are not normally lost.

How can u master reset an tomible HTC HP2 phone

You can master reset your HTC mobile using the unlock codes
in the site OnlineGsmunlock.com. you can easily reset
your HTC mobile. Do not enter wrong unlock codes. If you
enter certain amount of wrong unlock codes your HTC mobile
will be hard locked and sometimes becomes unusable.

How can I reset my htc white and silver at