When i hit ctrl alt del this thing pops up...

could be a problem with a corrupt data packet that looks for the shortcut in this case the ctrl-alt-delete. Just run a chkdsk /r and it should repair any broken sections to do this first turn off your computer then start it up in safe mode with command prompt (press F8 when windows is starting up) then type chkdsk /r into the command line and wait while it repairs the corrupt sections. This can take a while depending on how much is broken