Windows 7: Cannot pin application to the taskbar

Is it possible to change a pinned icon in windows 7?"

To change a shortcuts icon that is pinned to the taskbar can be done indirectly... The easiest method I've found is to drag it to desktop, unpin it, modify it, re-pin it.

I have a couple of command prompts that start with different environment variables and a couple of applications with the generic "Application Icon", is there any way to give them different icons?

If you have a shortcut for each of the command prompts each of them can have there own individual icon. Right Click properties, change icon, select an ico or exe file, or create an ico and hunt down it.

Also is there anyway to pin a shortcut to the taskbar?

Right Click > Pin to Taskbar (from startup menu) otherwise just drag it there.

Try Ctrl + Shift + RightClick to get to properties but visual changes to the icon are not updated even after reboot. I guess that it is cached somewhere. I'll let someone more knowledgeable jump in and that facet answer.

Sorry, I fumbled the answer at first. Have I answered your questions; or would you like me to expand or rephrase anything.

After some research, I found a hidden folder

%appdata%\Microsoft\Internet Explorer\Quick Launch\User Pinned

I had searched around here, thinking that Quick Launch and Taskbar pinning were very much the same, but I hadn't seen it because it was hidden. In that folder, there was a shortcut with the desired name. Why that shortcut didn't appear on the taskbar, I don't know. I deleted that shortcut, then re-pinned the application, and it now appears with the correct name.