Flash installation problem

I've installed Flash several times while logged in under my name on our home computer.  Even though it says installation is complete, when I try to use an app with it, it says it needs to be installed. Its already installed on this computer and works fine when my husband logs in under his name.  I've tried approaching it different ways like installing it when prompted from an app, going to the Adobe site to install it, etc.  I am using Internet Explorer and sometimes it says I need to close it to complete the installation.  I do this and it says it installs it, but it apparently doesn't.  It doesn't always give me the notice to close Explorer; only sometimes.  Any suggestions?  Thanks in advance.