CPU usage 100%

[#1]

I have four programs running.... CW communicator... CW com QRZ list ( list of calls on a open office spread sheet)  Email inbox with thunderbird and this forum on firefox latest version....
When trying to use my morse key on CWCOM... it gives corrupt morse symbols..... doing CTRL ALT DEL shows the CPU usage at 100%.  going down the list of processes running... Firefox is showing between 30 and 60  with 342,600k  on on the memory column..... apart from taskmgr.exe showing 03 and 2,200k on memory... everything else is showing 00
How can I find out what is causing the cpu to run at 100% ?  ( cwcom.exe  is showing 00 )

[#2]

Try selecting - Show all users - that should hilight it

[#3]

Thanks jim.... looks like svchost.exe ....    SYSTEM  ..... Host processes for windows services  alternating between 00 and 11.... is working with stacsv.exe  ....  SYSTEM  ....  IDT PC AUDIO ..alternating between 45 and 90
which, .... i`m thinking.... "could" be linked to CWCOM... ( as it uses the audio to produce the morse sound )... however, that is not in use and on "standby" until I start keying...  everything else is at 00
Have closed CWCOM... and it still shows 100%.... 

[#4]

Whatever it is... isn`t doing it after a reboot..... however... when I opened firefox it shot up to 100% for a short while, and now fluctuating wildly between 40 and 70 percent.  (sometimes pushing the overal figure to 100 percent )  physical memory is 36 percent and 79 processes are listed...

[#5]

Something isn't right
I have a gadget on my desk top - http://pcsupport.about.com/od/toolsofthetrade/gr/cpu-meter-gadget.htm (Win7 and Vista) which allows me to see what is happening

[#6]

Try this , it may help in finding what is using what 
http://technet.microsoft.com/en-gb/sysinternals/bb896653.aspx

[#7]

do you use a USB mouse ?
if yes is it an advanced mouse that allows you to change its response rate (polling rate)?
if yes have you changed the frequency from the default 125Hz?
if yes put it back to 125Hz,
the problem technically speaking is PCI bus saturation, even if the device is set lower than 125Hz,
failing that it could be a need to upgrade the audio driver from the IDT website, or an incorrect Morse driver (again a polling rate issue if its a USB device)

[#8]

@ nanotm..... yes it is a usb mouse... but a cheapo basic optical unit.... ( two for £5 on ebay )... this has been happening for quite some time.... I only notice it because of the corruption of my keying on CWCOM... when ... no matter what symbol I make with the key.. it comes out rubbish as if something is taking control .... it works on a processing time system somehow.. ( not sure of how ...so that is the best description)... it is a bit like " stuttering " on you tube videos,... and they sometimes "halt" with no reason... like buffering... then start up again...
@ Old Jim.... yes... gadgets are nice...if you know what they are telling you... and this problem is "annoying"...when it happens, but does not happen all the time... with a gadget..it will tell me that the cpu is overworking..but will not tell me why.or what is causing it.... so just the same as using CTRL ALT DEL... and reading it off the bottom  !..
@rongtw..... ok...have downloaded and installed that... but will have to spend some time to understand what it is trying to tell me..... at present... everything is (seems to be ) working fine... so will have to wait for the next time it happens.... and then check to see what is going on...
Thanks for everything so far, guys..... will leave it at that for now.... maybe I can track it down, and will come back if I have any more questions....

[#9]

it will either be a device conflict an out of date driver or a response rate frequency,
and if the morse key is usb based then its most likely to be a polling (response) frequency that's causing the problem

[#10]

shutter i see this often also and i use seamonkey - firefox but with a developers theme (also better with memory management).
In my experience it is the flash player that does this devilish deed. On some mozilla browsers it runs as a seperate process called FlashPlayerPlugin on others it runs as part of the main browser program. What I ended up doing was setting the flashplayer to be disabled and ask to be enabled on each page.
Anything from a badly coded advert (O2 are great at using CPU cycles in their flash ads) to a video advert can hog the CPU cycles. O2 got a roasting off me a year or two back for this and I sent them a TON of screenshots proving what their adverts were doing - they got back to me a week or two later saying that they'd got their dev team to fix the problem and indeed the next time i saw their ad the cpu usage had dropped drastically.
Try disabling your flashplayer plugin and see what happens to firefox's cpu usage.

[#11]

Should I take shutters long silence as my answer having been the cure to the problem?

[#12]

Not sure.....  :D....  since my last  ( and yours)... I have had problems with playing youtube vids.... snowy screen with a message in the middle.... have not disabled anything.. !... so I downloaded and installed Flash Player.... ( already installed as I am watching you tube every day... ).... and that day... problem solved.... next day... same snowy screen ..... same message... same action... downloaded and  installed Flash Player.... again !... and it has cured the youtube vid problem.... ( so far so good... ).... haven`t had the issue of 100% CPU ... so don`t really know what happened.!... seems to be working ok.................for now....