while using remove tool stroke marking Z key for zoom tool not working

Try to reset the preferences of Photoshop first by using the steps described here:

https://helpx.adobe.com/photoshop/using/preferences.html#reset-preferences

It's recommended to backup your settings before resetting the preferences.

See here:  https://helpx.adobe.com/photoshop/using/preferences.html#backup-photoshop-preferences

If this doesn't help, provide a copy of your 'System Info'. This can be get from the Photoshop menu item Help > System Info. There's a copy button in the System Info dialog. Press this button and paste the info into your next forum post.