Here is how to completely remove flash cookies from Windows XP, Vista and Windows 7.

For Windows XP users: Run CCleaner and add the following two folders to the Include List. For that go to Options – Include – Add Folder, and then navigate to:

C:\Documents and Settings\ User name\Application Data\Macromedia\Flash Player\#SharedObjects

C:\Documents and Settings\User name\Application Data\Macromedia\Flash Player\macromedia.com\support\flashplayer\sys

Now add the following file to the Exclude list. For that go to Option – Exclude – Add file and browse the following file.

C:\Documents and Settings\ User name\Application Data\Macromedia\Flash Player\macromedia.com\support\flashplayer\sys\settings.sol

For Windows 7 and Vista users: Add following two folders to Include list

C:\Users\User name\AppData\Roaming\Macromedia\Flash Player\#SharedObjects

C:\Users\User name\AppData\Roaming\Macromedia\Flash Player\macromedia.com\support\flashplayer\sys

In the Exclude list add the following file:

C:\Users\User name\AppData\Roaming\Macromedia\Flash Player\macromedia.com\support\flashplayer\sys\settings.sol

[Note: 'Please enable ‘Show hidden files and Folder Option before proceeding. For Windows XP go to Windows Explorer – Tools – Folder Options – View and enable ‘Show hidden files and Folder’ option. For Windows 7 & Vista got to Windows Explorer - Organize - Folder and Search option - View – and enable ‘Show hidden files, folder, or drivers’] - [Via]