General Computer Questions

CD Tray keeps randomly opening with no disc inserted.

Tried to get on another computer and my friend didn’t know his password. Every time I turn on the computer his router comes up and I have to reset to my home router. How can I get rid of his location he lives hundreds of miles from me

my mouse seems not to respond when moved sometimes. I can also hear a warning sound when it does. what should i do?

two computers, Dell with XP and HP with 7 connected with a router. I am using the Dell (XP0 and not able to return to the HP. What step am I missing? The HP has a yellow light on – not the blue when it is working.