svchost.exe question

hi, how many of these are supposed to be in processes? because i have 6!!: 1 in local service, 2 in network service, 3 in system! also when i turn on the computer, for several minutes one of the svchost.exe in system uses 100%cpu, mem usage of 25,000 +-… after awhile it goes down to 5,000 +-… and this also happens sometimes randomly! this is new, like 2-3 days… the only stuff ive done recently are installing sp2 on home edition, installing windows defender (but removed - i thought it caused it, i was wrong) installed spybot and adaware, after removing old version… i also removed some other programs i havent been using!! i dont think its a virus! i am running nod32 and avg free how do i solve this?? any help would be appreciated thx

i am running nod32 and avg free

*** —>More is not better, when it comes to AntiVirus utilities.
Decide which one you want to keep and thoroughly uninstall the other one via Control Panel - Add/Remove
After you Uninstall one of the AntiVirus utilities, go to C:\Program Files\ and Delete any remnant leftovers from that uninstalled AntiVirus including the entire Folder for the removed AntiVirus.
(Running two or more AntiVirus products creates conflicts between the programs and can even defeat the protective functions that you would receive by running only one such utility alone)

http://support.microsoft.com/kb/314056

Svchost.exe is a generic host process name for services that run from dynamic-link libraries (DLLs).
MORE INFORMATION
The Svchost.exe file is located in the %SystemRoot%\System32 folder. At startup, Svchost.exe checks the services part of the registry to construct a list of services that it must load. Multiple instances of Svchost.exe can run at the same time. Each Svchost.exe session can contain a grouping of services. Therefore, separate services can run, depending on how and where Svchost.exe is started. This grouping of services permits better control and easier debugging.

It is not at all uncommon to have multiple instances of Svchost.exe running on a machine. It's normal, and in fact required.

Noticing that an instance of Svchost.exe raises to 100%, indicates that the process that is depending on Svchost.exe is "running". This is ordinarily "normal", but can be an instance of an annoying "auto-updater" from a utility that you don't even use, and can even be an instance of Malware accessing the internet to "phone home" with information gathered from your machine.

Rather that worrying about how many instances of svchost.exe are running, be sure to run scans for Malware to keep your machine clean, and uninstall or disable unnecessary updaters and utilities that you do not use.

Best Regards