In tip 2060, I explained the Svchost process in Windows 2000.

In tip 4310, you can see multiple Svchost processes in Windows XP.

%SystemRoot%\System32\Svchost.exe is a generic process name for services that run from dynamic-link libraries (DLLs). When you start Windows XP, Svchost,exe constructs multiple lists of service groupings that need to be loaded. Each instance can run at the same time. Svchost,exe groups are delineated at:

HKEY_LOCAL_MACHINE\Software\Microsoft\WindowsNT\CurrentVersion\Svchost.

Each Value Name contains a list of included serviceDLL values, in a REG_MULTI_SZ data type. These servies are extracted from HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\.

To see the list of active services in each process, open a CMD prompt and Type:

Tasklist /SVC

The following was displayed from one of my Windows XP Professional computers:

Image Name PID Services
====================

= =============================================
System Idle Process 0 N/A
System 4 N/A
smss.exe 372 N/A
csrss.exe 484 N/A
winlogon.exe 512 N/A
services.exe 572 Eventlog, PlugPlay
lsass.exe 584 Netlogon, PolicyAgent, ProtectedStorage,
SamSs
svchost.exe 748 RpcSs
svchost.exe 816 AudioSrv, Browser, CryptSvc, Dhcp, dmserver,
ERSvc, EventSystem, helpsvc, lanmanserver,
lanmanworkstation, Messenger, Netman, Nla,
Schedule, seclogon, SENS, ShellHWDetection,
srservice, TermService, Themes, TrkWks,
uploadmgr, W32Time, winmgmt, WmdmPmSp,
wuauserv, WZCSVC
svchost.exe 920 Dnscache
svchost.exe 964 Alerter, LmHosts, RemoteRegistry, SSDPSRV,
WebClient
spoolsv.exe 1048 Spooler
explorer.exe 1328 N/A
TaskSwitch.exe 1484 N/A
taskmgr.exe 1512 N/A
point32.exe 1536 N/A
msmsgs.exe 1560 N/A
fastkey.exe 1568 N/A
IEXPLORE.EXE 1580 N/A
prntscrn.exe 1596 N/A
SetiSpy.exe 1604 N/A
setiathome-3.03.i386-winn 1676 N/A
svchost.exe 1828 stisvc
UdServe.exe 1852 UndeleteService
Fast.exe 1984 InteractiveLogon
dllhost.exe 1224 COMSysApp
msdtc.exe 1208 MSDTC
wmiprvse.exe 3056 N/A
cmd.exe 3428 N/A
tasklist.exe 3460 N/A
The matching registry entries are:
Key Name: SOFTWARE\Microsoft\Windows NT\CurrentVersion\SvcHost
Name: imgsvc
Type: REG_MULTI_SZ
Data: StiSvc

Name: LocalService
Type: REG_MULTI_SZ
Data: Alerter
WebClient
LmHosts
RemoteRegistry
upnphost
SSDPSRV

Name: netsvcs
Type: REG_MULTI_SZ
Data: 6to4
AppMgmt
AudioSrv
Browser
CryptSvc
DMServer
DHCP
ERSvc
EventSystem
FastUserSwitchingCompatibility
HidServ
Ias
Iprip
Irmon
LanmanServer
LanmanWorkstation
Messenger
Netman
Nla
Ntmssvc
NWCWorkstation
Nwsapagent
Rasauto
Rasman
Remoteaccess
Schedule
Seclogon
SENS
Sharedaccess
SRService
Tapisrv
Themes
TrkWks
W32Time
WZCSVC
Wmi
WmdmPmSp
winmgmt
TermService
wuauserv
BITS
ShellHWDetection
helpsvc
uploadmgr

Name: NetworkService
Type: REG_MULTI_SZ
Data: DnsCache

Name: rpcss
Type: REG_MULTI_SZ
Data: RpcSs

Name: termsvcs
Type: REG_MULTI_SZ
Data: TermService