Files opening as loging in

Hello,
I have this strange acting of my PC, as soon as I turn on my computer two files constantly open, I've run a thorough virus scan twice and there is no virus, I don't know where to look to fix this. Also one day I turn on my PC and somehow It seems that the appearance - fonts, graphic etc. has been changed, this has happened after I've run a registry cleaning program Advanced System Optimizer, Please anyone some suggestion of a solution.
Thnx