I had this issue for a few weeks where the pc would hang when closing a Chrome tab. Solutions varied from testing RAM with memtest or Windows Memory Test, closing any backup plan running and updating Nvidia graphics card drivers. The graphics card driver update worked for me. In the google group here bdericks was the first to mention this issue.
The issue returned, found another possiblesolutionn. Disable from //chrome/plugins/ the embedded Flash player, install the player from Adobe, restart chrome. More info here