When I find an odd file somewhere on my system, I do a Google Search on the file name, in this case it would be on: tw0001.dat
I'll then go through a large enough number of the hits to confirm a consistent answer, giving more weight to those found on legitimate anti-virus scanning software sites (and OS provider sites - e.g., Microsoft, Apple), followed by what I would consider as legitimate tech sites.
FWIW, I did a Google search, looked at a couple of the hits, which seemed to indicate this file contains start-up scripts associated with CS2, CS3 (and I would presume any other more recent version of Photoshop).
However, don't take my word on this (I did not look long), Google it for yourself and so that you are comfortable with your findings as it is your computer you are worried about.
Regards,
