A preview handler is a plug in that allows you to view a file in Windows Explorer (Vista and Windows 7) and in Outlook (2007 and 2010).
For well over two years, the installation routine for Adobe Reader has had an error which prevents the preview handler from being properly installed in 64-bit systems. We came across this site that published an installer to correct the error. Works great – thanks!
It’s hard to understand why Adobe doesn’t fix the error. Very strange.