since you paid perfectly good money for CATS tuner (a commercial package) i'd suggest contacting him to figure out why you're getting that error..? it shouldn't be doing that. you're probably just missing a library or maybe it's a compatibility issue with newer versions of windows as it's quite old software.

i tuned with tunercats for years. it works great. his flashing routine is really reliable. winflash and tunercat have the exact same flashing thing, it's just winflash is stand-alone for people that dont want to buy tunercat and use something else for bin editing.

not trying to sway you over to my stuff (not that i have anything to gain anyway and i'm sure tunercat will work fine for you) but one reason i started messing about with tunerpro definitions and started using tunerpro is that tunercat is really god damn awful at categorizing tables. it just has a giant menu with a bunch of tables, so to find everything you want, it's basically sifting through a list of text. since one of the most important parts about tuning software is locating the table you need to modify that always bugged me. tunerpro allows you to specify a categorized list of tables, so with tunerpro and my definition file you can have a list of fuel tables, a list of idle tables, a list of spark tables... also there's lots of info and tooltips for each table whereas with tunercat you're mostly on your own to figure out what something does. might want to give it a second shot. you can use all of these tools side by side.