Toolbar items suddenly not showing ?

    For some reaom my taskbar is missing the icon for ejecting or undocking attached devices to it ,also the double arrows for showing all icons and hiding the icons also is missing ?   I have tried checking and unchecking the options in the taskbar and start menu properties and still the problem persist . I would greatly appreciate anyone that could tell me how to get my taskbar back to showing these missing items ! I have no idea why these things are suddely not in my taskbar ,usally I would use it B/4 removing a flash or jump drive from the system ? Thank you an advance to anyone that replies ,also I have tried a fresh reboot of the system and still no luck ,system restore will not restore my PC to any of the resotre points I chose  ? Thats another problem for another day ?

              Take Care ,Nick (Gumba) 

On edit, I just noticed the speaker icon is also no longer showing ? followed instructions in help and support for putting the speaker icon on taskbar ,did not work ?

XPS400 2.8Gig 820 D Dual Core -VIIV
O/S WinXP Media Center Edition 2005
3 G.B. DDR2 RAM PC5300 - 2-1G.B. 2-512M.B.
Samsung Hard Drive 250G.B. 7200RPM
Seagate externial 320G.B. H.D.7200RPM USB
ATI 128M.B.HYPER Mem PCI-E X16 X300SE.DIM
ATI TV Wonder Elite PCI
19" FP
Sigma-Tel Intergrated Audio 7.1 channel
Logitech G15 Keyboard
DVD-/+RW & DVD-ROM
Pertelian X2040 ForeSight Systems LCD information Display
Dell 944 AIO Printer
Sytem Blower Slot Fan
EASYWATCH LCD System Monitor /Fan Controller