I recently downloaded a trainer, and even after making AV exceptions and the like, when I open the trainer, it closes itself in less than a second. I've tried everything I can think of to fix it, but nothing works.
You will need to completely rule out your AV by attempting to run your trainer after temporarily uninstalling it or running in clean boot mode (both options will leave your machine without AV protection so it would be best to not use your computer for anything else during troubleshooting).
--------------------------------------------------------------------------- Your bitterness, I will dispel
I have exactly the same problem. No AV installed(windows defender is fully disabled) at all(my home network is firewalled and regularly scanned by several AV scanners). It happens with SOME trainers, not ALL of them.
OS: Win7SP1 x64(all latest updates installed). RAM: 16GB DDR3 CPU: i7 3770k MB: Maximus V Formula(ASUS)
Examples of trainers that worked for me: Brutal legend, WH4k down of war soulstorm. Examples of trainers that close after start: oddworld stranger's wrath.
Can you examine initialization of these trainers to compare and find the bug?