Forums mIRC Help In Windows Vista can't start mIRC

Very strange situation. The only thing I can think of is if you've disabled something specific like Data Virtualisation or the Application Information System but if that were the case I would have expected disabling UAC to fix the problem (I'm only guessing though since I don't have Vista available to check).

The good news at least is that the next version of mIRC should be fully Vista compliant and so there should be absolutely no reason for this problem to occur once it comes out.