I know my fair share of computers and such but when it comes to the majority of software and especially CCleaner and winapp2.ini, I'm pretty damn clueless as to what things do what. After having enabled pretty much everything in CCleaner for Firefox (excluding the corrupt sqlites, I believe) and run it a few times every now and then, my Firefox won't start properly (tried on two brand new Windows installations and two different Firefox versions, Aurora and Nightly, with the same CCleaner settings). When I click the firefox.exe it starts, but in the background and it stays there. I can't actually use it. I dunno which settings caused the error but I'm pretty damn sure it's something with winapp2.ini as this has never happened before.
P.S. I'm on a brand new installation now running CCleaner without winapp2.ini and I have as of yet to encounter this problem.