A few more thoughts about your problem based on Windows response of "Add to Google Chrome" when attempting to place a 'Yahoo Mail' shortcut onto the 'Quick Launch Toolbar'.
The 'Quick Launch Toolbar' is NOT the same as the Taskbar. Both are 'quick launch' but Windows treats each slightly differently.
The "Add to Google Chrome" response you are seeing indicates that you are attempting to place the 'Yahoo Mail' shortcut icon onto the Taskbar and as you have discovered does NOT accept the shortcut.
So, a couple of options,
Option 1
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To add 'Yahoo Mail' shortcut icon to the Taskbar without the need to activate the Quick Launch Toolbar, perform similar instructions as per my previous post, but enter a slightly different 'Location of item' as follows (assumes you are using the Google Chrome Web Browser) :-
- Right-Click a blank area of your Desktop
- Select 'New'
- Select 'Shortcut'
- In the 'Type Location of item' box, enter the following text (alternatively, to make it easier, suggest you highlight the following text with the mouse cursor and then use the Windows Right-Click, Copy and Paste method to enter the text exactly as shown, including the Quote marks and Space characters)
"%programfiles%\google\chrome\application\chrome.exe" "http://login.yahoo.com"
- Click 'Next'
- Enter a name for the Shortcut of your choosing e.g. 'Yahoo Mail'
- Click 'Finish'
- Right-Click and select 'Add to Taskbar'
You should now have 'Yahoo Mail' icon located in the Taskbar area.
Option 2
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As an alternative, (which you may not need if Option 1 is ok), if you have not already done so, you can opt to activate the Quick Launch Toolbar and when activated, the Quick Launch Toolbar sits alongside / integrates with the Taskbar where you can then perform the 'Drag' 'Yahoo Mail' to that Quick Launch Toolbar location.
To activate the 'Quick Launch Toolbar' there is some useful instructions at the following location showing how to perform the activation:-
http://winaero.com/blog/how-to-enable-quick-launch-in-windows-10/