If you are looking for a way how you could convert partial downloaded file - PART to JPG images, then you can't find it, because it is not possible. You might try to rename part to JPG and view it using some image viewer, but in most cases it will be corrupted and you will either see nothing, or only some parts. You need to re-download the file again.
Convert PTC Pro/Engineer CAD part to JPEG bitmap image format.
We found one software available in the database for this conversion.
Microsoft Windows software - convert part to jpg on Windows
A 3D modelling application
Convert from part file format
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.