Thanks everybody, sorry about the delay in my answers, I still have the computer for trying all the recommendations you told me. Well, reading the posts, I'm gonna try the following and I'll let you know what solve the issue. 1- Maybe you can try typing CMD instead of Explorer then at the command line type "chkdsk c: /f" and see if anything gets fixed. 2- Open task manager Open CMD Copy from somewhere else the same or closest explorer.exe versión to C:\windows or where %WINDIR%\ is. 3- CTRL + ALT + DEL and bring up task manager, file>new task (run) and regedit - HKLM\SOFTWARE\Microsoft\