I've seen this before with some customers, and it's so simple there is no reason to not check it.
You will need to check the add-ons within Internet Explorer, and ensure that Flash Player is currently enabled. When resetting IE to defaults one of the things it does is disable your currently installed add-ons. Additionally, if you have a "robust", bloated, security suite it could be managing related security settings which we can check as well.
Begin by opening Internet Explorer. You will want to select Tools > Manage Add-ons > Enable/Disable Add-ons. This will bring up a window with currently installed... add-ons.
What we're looking for is Shockwave Flash Object if you scroll to the right, within that window, the file name should be 'Flash9f.ocx'. You will see a "Status" column which should say Enabled. If disabled simply click Shockwave Flash Object, and click the Enable radial button towards the bottom of the window. Close the window, and close/reopen the web browser.
If that's not the case you can check the security settings to ensure that you can successfully "install" ActiveX components. This is done by opening Tools > Internet Options, and then the Security (tab). Click on the "Custom level..." button, and we are looking fort he ActiveX category which is represented by a tri-colored cube icon. We are looking for the "Run ActiveX controls and plug-ins..." option which needs to be set to Enable. If not already done so set it to enable, apply, and then close/reopen the web browser.
Check to see if the issue is resolved by visiting a website you know requires Adobe Flash Player. If you continue to have problems you may want to uninstall/reinstall the application, and/or reset the browser to defaults to disable possible conflicting add-ons.