Had bootstrapper.cpp error code. Found instructions for stopping/restarting Windows Installer Service (disable, reboot, reset to manual and start) to be the ticket. See: http://sherylcanter.com/wordpress/2008/12/another-installation-already-in-progress-but-its-not/ Turns out that some time ago, I had a failed Java update that apparently hung mid install. There were no processes that I could associate with it, but after I restarted the Windows Installer Service and initiated the Evernote install (no "bootstrapper" error - yeah!), the Installer gave some diagnostics and presented an option to roll-back the aborted Java installation. Everything proceeded without a hitch. Hope this helps.