Ctrl and Shift keys do not work for multi-selection in Windows Explorer

I have been using Windows 7 for quite some time and over that period of time, I have heavily customized numerous settings across the OS.

Unfortunately, the other day I encountered an unusual problem in Windows Explorer which prevented me from selecting multiple files using either the Ctrl key or the Shift key to highlight and select multiple items simultaneously.  I did not ever remember encountering this problem earlier in Windows 7 so I decided to do a bit of Googling.

As it turns out, this seems to be a common problem dating all the way back to Windows Vista.  It seems that it is common enough that Microsoft has published a Support Knowledgebase article detailing the problem:

You cannot use keyboard shortcuts to select more than one item in Windows Explorer after you install certain applications on a Windows Vista-based computer

http://support.microsoft.com/kb/934548/en-us

Interestingly enough, the solution is quite simple:

To resolve this issue, use the Reset Folders command. To use the Reset Folders command, follow these steps:

1. In the Windows Explorer window where this issue occurs, click Organize, and then click Folder and Search Options.
2. On the View tab, click Reset Folders.