Can't shut down completely/whirring sound...

I have an HP computer, about 4 months old, and have been having a problem shutting it down. When I do start, shut down, it turns almost all the way off (i.e. monitor goes to sleep, blank screen, etc.) however the blue light on the power button stays on. I then have to hold it down in order for it to shut off.

Another issue I have been having lately is a whirring sound inside my CPU. It almost sounds as it does when the computer is trying to read a cd, but there is nothing in the drive. I don't know much, but do computer's have fans? It has been really hot here lately, could that be what it is?

Some other things: I have windows XP. My roommate just connected a wireless router (Linksys) to my computer to use with her laptop (the router is brand new). The whirring sound seems to have come about at the same time as the router...could the two be related?

Let me know if there is any other information I can/should provide.

Thanks! Lisa

 

some pc's r like that