Another program with the set of features you're after is Autohotkey.
Autohotkey has many automation features, amongst them is
Create hotkeys for keyboard, joystick, and mouse. Virtually any key, button, or combination can become a hotkey.
You can specify any set of hotkeys that you like and then specify a script or command to run upon detection of that hotkey.
There's a brief set of tutorials here. But as an example if (after installing Autohotkey) you create a script (e.g. myScript.ahk) with the following
#n::
Run http://www.google.com
Run Notepad.exe
return
and run it you will get a little "A" in your system tray. If you press Windows+n it will run whatever program is associated to open URLs, then proceed to run notepad.
If you just want single hotkey to single command then
#n::Run Notepad
^!c::Run calc.exe
Windows+n will run Notepad, and CTRL+Alt+c will run calc.exe
As you can see you can have a multitude of hotkeys in one script, ready to run whenever you like.
The turtorial and other documentation is quite good, check it out.
-=EDIT=-
To answer your comment:
Generally I would expect the hotkeys to be a combination of keys to be pressed (and held) at the same time, the problem with typing "c h r o m e" is that you'll never be able to go to a website such as Superuser and ask a question about chrome without it coming up with a new window for your browser.
What you are after is doable though, using hotstrings in Autohotkey. typically these are used to expand abbreviations so (as in their example on the page I just linked) you can type "btw" and have it automatically replaced with it's full form of "by the way".
From this documentation page I would expect the following to do what you expect:
::chrome::Run chrome.exe
Though I would make the "chrome" something less likely to get typed in the normal course of using your computer, perhaps chrme
or something, though that doesn't rule out spelling mistakes (of "charmed" or similar) annoying you.
To do this simply as a hotkey (all pressed at the same time) I would expect it to look like this:
chrome::Run chrome.exe
Note that a hotstring line begins with ::
while a hotkey line does not.