Hi, The problem began when I downloaded some rogue file. Then msconfig, regedit, services.msc and cmd stopped working. However after carrying out the 8 initial steps outlined in this forum, all the others started working again except cmd.exe. When I try to run it, I get an error message saying Windows can't find 'cmd.exe', even though it is in the system32 folder. Now the funny thing is when I renamed the cmd.exe to xcmd.exe, it works just fine, but the replaced file cmd.exe still won't work, and I need it to work. I tried RatsCheddar and that still didn't fix it. Please find attached my avira, malwarebyte, superanti spyware and hijackthis logs. I'll appreciate all the help I can get. Thank you.