when desktop starts, screen lights up but neither mouse, keyboard, nor touchscreen are working

[Alex0606]

when desktop starts, screen lights up but neither mouse, keyboard, nor touchscreen are working

[itsmyname]

@Alex0606 -- by "starts up", what do you mean?

When you power-on the computer, what immediately shows on the screen (white text over a black background) ? Any "beeps" ? Any repeating pattern of blinking lamps, e.g., "short-short-pause-short-long-pause" ? Any error-messages? Anything like "press ESC to enter Setup Mode" ?

It could be a failed disk-drive, a failed motherboard, or a failed power-supply.

I recommend that you find a computerphile friend, or a professional computer technician, for trouble-shooting.

Is the original one-year HP Warranty still in effect? If so, then you can make a claim against the warranty, to get HP to fix it, at their expense.