Google Chrome gets updated very often. You may not have noticed it because Google automatically updates and installs the latest stable version of Chrome. Even Firefox is trying to play the catch up game but I still don’t think they will ever catch up when Chrome is already at version 16 now and Firefox is only at v9. Whatever the case is, have you ever wondered what goes on when Google Chrome is being updated? Will the new version overwrite the old version? Or does the old version gets uninstalled automatically? The answer is the previous version of Google Chrome are kept and not removed. If you check the folder where Google Chrome is installed, you would noticed that there are 2 folders with different version numbers and two chrome executable files (chrome.exe and old_chrome.exe).
Obviously chrome.exe with the newer version number are the most updated Chrome while old_chrome.exe and the folder with older version number is obsolete. One probable reason that the old version is still kept because of rollback purposes but the official Chrome FAQ page mentioned that they don’t recommend you to roll back Google Chrome to a previous version.
On Windows XP: C:\Documents and Settings\<user>\Local Settings\Application Data\Google\Chrome\Application
On Windows Vista/7: C:\Users\<user>\AppData\Local\Google\Chrome\Application
Delete old_chrome.exe file and the folder that shows an older version number. Alternatively, you can use a free and portable tool called OldChromeRemover which automatically detects the obsolete versions of Google Chrome and deletes it when the user press the Y button on the keyboard. OldChromeRemover requires Microsoft .NET Framework 3.5 and also Run as Administrator to work.