Hi, I have tried to install win 8 themes in my Win 7 home premium. Few DLL changes were suggested there. After making those instructed changes, it was required to restart the system. Before that it was instructed to disable UAC. I forgot to disable UAC and restarted my laptop. Now I am seeing welcome screen without displaying logon window. And now I am not able to logon in the system any more. I am struck here. We have removed all passwords using bios. But still system is struck in the same screen. I am not able to get into the system in any way including command prompt. I have some critical data in my C drive. Anyone of you please help me out to get me out of this trouble. I want to save my data. And system is showing no error message or crash message. Thanks in Advance.