Hi there
I am having trouble installing gmail notifier
The below error shows on 'chrome://extensions/'
"Could not install extension from 'D:\...\Downloads\gmail.crx'. bad version number"

I have changed the shortcut target to "C:\...\chrome.exe" --enable-extensions
When I click on the 'Install link' at 'http://dev.chromium.org/developers/design-documents/extensions/samples'
it does not prompt to install, all it does is download to my PC and gives the error on the extensions page.
I have tried running it from explorer, dragging it into a Chrome window all with the same result.

I am running 2.0.172.37
Windows XP, SP3

Please advise if I am missing something
Thanks for your help

2.0.172.37

there is your problem. stable versions do not support extensions. download dev from here.
it is even written on the page you posted,

To run these samples:
Use a recent trunk build or the Chrome dev channel release.
Add --enable-extensions to your Chrome command line.