I have a used iMac that I was given. The person this computer belonged to passed away a couple of years back and we have no idea what the password on it is. I Googled how to over ride the password and found what appears to be a legitimate way of resetting the password. The problem though is this, the instructions tell me to hold the Apple + S key right after the chime. I should then get a text prompt to enter in four different commands. I however do not get this text prompt. The computer would just continue to boot into the operating system. I tried numerous times and now I cannot even get it to boot into the OS. Instead, it comes up with what looks like a blinking planet earth icon. I cannot click on it nor do anything with it. I have never used a Mac before and the only reason I got this one is so I could become familiar with Macs before one of my upcoming classes. Now I have a file folder with a blinking question mark inside of it. One other thing, I do not have the Apple keyboard or mouse. I'm just using a regular pc keyboard and mouse. Thanks.