It's not one of those things where screenshots can be easily given (at least by me,anyway) - I still think you should have posted this in the TS2010 forum.
I have the same problem. I reinstalled my windows and then I installed the Trainz, and I can't update it from 42203. Neither when I use the original patcher (avialble in the Launcher). It always writes that patching aborted, because "Error while reading patch data". I've tried it many times, but it didn't work. So I didn't patched it. After a while the game won't suggest you to patch trainz.
I downloaded now the "42203 to 44088" patch file, and it didn't work. I put it into the TS2010 directory and then opened. And it worked. I selected the trainz.exe and then it is patching right now. Maybe it'll work for you.
I strongly do not advise running Trainz without patches.
Firstly, reinstall the game as the patch has probably messed something up.
Once that is done, install the 42203 to 44088 patch from http://download.ts2009.com/patch/42203_to_44088.exe - make sure you turn off your antivirus and internet connection whilst patching if possible, as to avoid problems.