PNG can be considered original, but it depends on application. It can save pixels loslessly, but don't count on layers or other metadata be preserved. Some applications, like Fireworks, are able to save layers in PNG, but that's non-standard thing and won't work elsewhrere.
There is no online site that edits MP3 files, but you can download Audacity and edit MP3 files for free.
Protects a the user from viruses which are destructive. A virus is malicicious that delets add and/or edits files.
It is called backing up files. It is used in the event the original files are lost for some reason. That way there is a backup to fall back on.
Chatterbots.org has a link to the source files. Type in Parry and click the download link which should take you to a archive of the original files. From there you c an see the Parry files and components. The archived files are not in executable form so you should have to poke around to figure out how to run PARRY.
Files
It is your decision. There are reasons for keeping them and reasons for deleting them.
you copy all the original files to a another hard disk or flash drive before formatting the disk with the original files
Making a backup
Settings from the original office might be lost with everything else if you upgrade, but unless you put your files in the same folder with the office applications, you should not lose files.
Backup files.
Usually from torrent websites such as piratebay, mininova, sumo torrent, but i think you'll need a pokesave, which edits the games save file.
The difference between the Regedit and the Scanreg utilities is that the Scanreg creates backup for your registry files. The RegEdit edits the registry.