I loader a new program to my systerm : vists , it to make windows look and feel like vista , I loader it , ater that the systerm ask me if want too restart the computer and I did it , when it when on again I did not want to load the new soft were , so it on reading window , but does not open , do not have a disk that I downloader the software for , downloader it for internet , and also do not have a rebooth dics , what must I do to reboot my computer without losing my files ! Please help , thanks marco

Boot to SAFE mode and run a system restore.