To convert files with the Cometdocs interface, you need to first upload them into the Clipboard. If you are not a premium user, you will be able to upload and convert only one file at a time. Premium users have the ability to convert multiple documents at the same time. Once you have uploaded the file to your Clipboard, drag it to the Convert Tab.
Alternatively, if you are a registered user and have files already stored in your Host tab, all you need to do is drag them to the Convert tab.
The list of all the possible conversion types for the format you have uploaded will now appear. Choose the needed format, and click Convert.
If you are a registered user, you will be redirected to the Store tab, where you will be able to keep track of the file conversion process.
Unregistered users will have to enter their email addresses and check their inboxes, which is where the newly converted files will arrive after several minutes.
Keep in mind that conversions might take a while depending on the file format and size.
For a list of all possible conversion file formats, check this link.