Depends....
Go to Start/Control Panel/Sounds and Audio Devices. On the Volume Tab under
Device Volume, put a check in the box that reads: Place volume icon in the
taskbar.
If that has been tried:
Place your XP CD in then go to Start/Run and type in:
EXPAND -R X:\I386\powrprof.dl_ C:\Windows\System32
Once done: Go to Start/Run and type in: regsvr32 stobject.dll
If the above hasn't helped and you have received this error:
Windows cannot display the volume control on the taskbar because the Volume
Control program has not been installed. To install it use Add/Remove
Programs in Control Panel.
To resolve this issue, extract a new copy of Sndvol32.exe from the Windows
XP CD to the system_root \System32 folder on your computer's hard disk. To
do this, follow these steps:
Start/Run/CMD. In the command prompt window type:
X: (where X is your CD Drive letter)
CD \I386
Then use the expand command:
expand -r sndvol32.ex_ c:\windows\system32
Note: This assumes XP is installed on C: and that its installed in the
Windows folder. If not, you'll need to adjust the command accordingly.
Additionally, this must be an installable version of XP, not a "recovery
CD".
Restore Volume and Net Icon to Notification Area (Line 320)
http://www.kellys-korner-xp.com/xp_tweaks.htm
Troubleshooting the Volume Control Icon
http://www.kellys-korner-xp.com/xp_v.htm#volume
Volume Icon Is Displayed Incorrectly in the Notification Area After the
Computer Resumes from Standby
http://support.microsoft.com/default.aspx?scid=kb;en-us;828694&Product=winxp
Troubleshooting the Notification Area
http://www.kellys-korner-xp.com/xp_n.htm#na
--
All the Best,
Kelly (MS-MVP)
Troubleshooting Windows XP
http://www.kellys-korner-xp.com