Hello everyone. It has been long since I posted anything. I have question for you today. I have Satellite A205-S5871 toshiba laptop which runs Vista home premium. Until a while ago, it worked properly. But before two weeks, a virus attacked it (it failed to boot and I think it is because of virus, though I am not sure). Then I copied and pasted the missing dll files(MSIMG32.dll, sfc.dll, SFC_OS.dll & nt.dll which I downloaded from internet not from Microsoft) into the windows\system32 directory and it booted. But now it doesn't play video or any audio. When I try to play in WMP11, it gives error message Windows Media Player encountered problem while playing the file. For additional assistance, click Web help. I clicked the web help and tried to do what is recommended but it did not work. I also tried to reinstall audio and video driver, still no effect. on the web help, it reads This error might have been triggered by an error in another program or component of Windows. The following information describes the original error. Original error message: 80070241 What do you advise me? The audio player is Realtek High Definition Audio, and video is Intel 965 Express Chipset family. Additionally, every time I launch any program, an error message The Ordinal 7 could not be located in the dynamic link library sfc_os.dll appears. Any reason or solution?