Toshiba satellite L305D touchpad wont accept clicking

uninstall and resinstall the drivers like HamStab said.

if your double click/double tap on the pad itself and it works yet the mouse button does not work then you may have a button broke.
if its under warranty get it fixed as soon as possible before the warranty runs out.
I've actually seen this alot where the left mouse button gets used enough where it will fail.

if the button did fail then your only options are.
repair the button via warranty
or repair the button from getting parts from ebay.
Use double tap on the pad. and ignore the button.
set your mouse to be a lefty mouse (which reverses the buttons)

maybe it could be the windows vista options

which is the option to turn on/off the touchpad

This wont be a vista option but an application that comes with Toshiba. I know they have Synapsys drivers on some laptops that will have an icon in the task bar, not sure for toshiba laptops though. Check the task bar and see if you see anything like Synapsys or anything to do with a mouse/touchpad. Might have some options in there for "clicking"

If the touchpad isnt working at all, there will be a function key that you need to press. like FN + 6 if that is the key for the touchpad.

touchpad is working for moving the cursor around the screen
but
cannot be clicked and select items

if the mouse pad works, it's not turned off.
it can be a bad pad ...did you already reinstall / update the driver ?
first thing to do imo

the left/right buttons below the trackpad work

the trackpad can move the cursor, but can not be pressed

Alright so it sounds like a Synaptics setting isnt set right. I have a toshiba laptop here at work that im messing with so i might be able to help you. On your task tray (by the clock) you will see a square with two small squares at the bottom, looks exactly like the touchpad on your laptop. Double-click on it if its there. If not, then go to Control Panel, and open the Mouse Options. Click on Device Settings (red logo next to it with a weird design), click on "Standard Pointing Device" under Devices, and then click Settings button. Reset all areas to default (button is on the bottom left). Try to click using the touchpad again.

If you didnt find any of the things i showed you above, you need to download the Synaptics driver, or touchpad driver, from Toshiba website, http://www.csd.toshiba.com/cgi-bin/tais/support/jsp/home.jsp?nav=Download  Your model number and everything is on the bottom of the compute ron one of the stickers.

installed driver, pressing the touchpad still doesnt work

could touchpad press be a selectable option

the touchpad usually is not a selectable option, though i know on the HP's computers you can turn them off via button. (this could extend to compaq becuase HP ownes them.)

also the synaptics software does install a small icon in the right corner(system tray) which can be turned off and on.  check the icon to see if it has the dreaded red x on it.

can this option be toggled using control panels
because I dont see touchpad icon in bottom right taskbar

It can be. If you go to Control Panel, Click on the Mouse options and it should be the last tab, might be Device Settings.

I would completely remove the driver from the control panel if there is no icon on your computer. Re-download from the link i posted above after uninstalling Synaptics Pointing Device or something similar.

how could I remove the driver from the control panel

only step I did.  Mouse reinstalled itself after restart.