Windows 7 keyboard on Desktop PC not working/PC won't respond

Hi, my desktop computer is currently turned on but the keyboard lights are all off and it won't display anything on the monitor if I click the mouse (which seems to still be working since the light is shining underneath.) I tried unplugging the keyboard and plugging it back in with no such luck. I pressed the power button once on the PC to try to wake it from sleep mode with no such luck. There's no power button on the keyboard that I can see and usually the computer light is a different color while in sleep mode but now it is remaining blue like it normally is when we're using it. This problem just started yesterday and I held the power button down to turn the computer off and then rebooted it normally and everything worked fine. I'm just wondering if there's a bigger issue and since I don't know much about computers, I'm afraid that my method of rebooting it might not be good for it in the long run. Especially if it's just a keyboard issue. Thank you so much in advance if you can help.

Hi there.

Just to check for more information. When you first power on the PC, do you hear any beep sound? Do you see the HP logo? Or you don't see any display after the "starting windows" animation?