When I open facebook on Windows 7 google chrome it hangs system for few seconds.
To resolve this issue open chrome.
In address bar type chrome://plugins and press Enter.
You will have list of installed plugins. click on “+ Details” button on top right side if list is not expanded.
Search for “flash” word and you will find two plugins files, one form operating system and another is from google chrome.
Disable plugin file from google chrome.
For reference view below image. it is from mac operating system. on windows you will have similar things but only different is path of plugin file.