When I first turn my computer on, the tower has what I would call a "normal" noise.  Randomly, it will go into what I call, "high gear," and sound as if it is working very hard.  This can last for a few minutes to several hours.  It will do this on and off whenever I have the computer on.  There seems to be no rhyme or reason to why it is doing this.  My worst fear is that someone has found a way to tap into my computer and is accessing it for whatever reason.  Does anyone know why this is happening?  Is it harmful to my computer?  Is there a way to make it stop?
Thank you.If this occurs when you are offline (or disconnected from a network) then you can rule out the cracker theory. You're PC has to be online for someone to access it.

Anyway, try updating virus and adware scanners and install a firewall.SLH.......Are you online or off-line when these activities occur?  Are you using dialup or hispeed ..?

What are you using for a firewall ?

What O/S are you using ?

let us know

DL65  Is this the fan you are talking about? If it sounds like a plane passing by, then you will know... lol   If so, then just open the computer case up, ground the electricity from your body, and clean the fan out...

[glb]Flame[/glb]Thank you so much for responding to me.  I'll try to answer all of your questions.  This happens both when I am on and off line.  I am connected through my cable company though, so does this mean I am online all of the time.

I always update and run my virus, adware and spybot scans.  I have McAfee Personal Firewall.

It is awfully loud, so I will try to clean out the fan.  Thanks for the suggesion.  Any more ideas?SLH......If you are going to clean out your pc as flame suggests....purchase a can off compressed duster or something similar.......pay particular attention to the heat SINK...( the thing that the fan sits on ) ......when you blow the dust off the fan blades ...use a chop stick or something ( non-metalic ) to prevent the fan from spining while you blow it out .......( the pc is turned off of course ) ....... Now ....when you say your pc is running when your not using it ....are you seeing hard drive activity ( the led light on the case flashing on and off )
Yes , you are online all the time unless you shutoff the connection in the control panel .

let us know

dl65 MAKE SURE THAT: When you go to clean out your fan, ALWAYS ground the electricity from your body BEFORE touching ANY system components! Good luck...

[glb]Flame[/glb]I know that I should probably know this, but I don't.....HOW do you ground the electricity from your body?
Thanks!
OK... What you have to do it touch the inner metal frame of the computer... So you will take your computer, and put it on a table OVER a tile surface... Next, take off the cover FRO your computer... Next, touch the inner metal frame of your computer... That's all!

[glb]Flame[/glb]