You cant install flash player for IE on Windows 8.1 using installer files because on windows 8.1 microsoft provides latest flash player with its windows update. Kindly perform the below steps
1. Perform windows update to get the latest version of flash player
2. Goto IE -> Tools -> Safety -> Make sure ActiveX Filtering is not checked
3. Goto IE -> Tools -> Manage Add ons -> Select "All add ons" in the drop down menu on left -> Make sure "Shockwave Flash object" is Enabled
4. Visit Flash Player Help on IE and click on "Check now" button and post the screenshot here using The specified item was not found.
I hope it solves your problem.