Okay, if it's telling you you don't have Java but you do then it might be an idea to clear out your Java files. Older Java programs conflict with the newest updates so you should do the following.
* Download the latest version of Java Runtime Environment (JRE) Version 6 and save it to your desktop.
* Scroll down to where it says "Java Runtime Environment (JRE) 6 Update 7...allows end-users to run Java applications".
* Click the "Download" button to the right.
* Select your Platform: "Windows".
* Select your Language: "Multi-language".
* Read the License Agreement, and then check the box that says: "Accept License
* Click Continue and the page will refresh.
* Click on the link to download Windows Offline Installation and save the file to your desktop.
* Close any programs you may have running - especially your web browser.
* Go to Start > Settings > Control Panel, double-click on Add/Remove Programs and remove
all older versions of Java. It is important that no older versions remain.
* Check (highlight) any item with Java Runtime Environment (JRE or J2SE) in the name.
* Click the Remove or Change/Remove button.
* Repeat as many times as necessary to remove each Java versions.
* Reboot your computer once all Java components are removed.
* Then from your desktop double-click on jre-6u7-windows-i586-p.exe to install the newest
Any problems carrying out the above, just post a query.
Let's see if that sorts out the problem.