While I don't recommend it, you can do the following to install Flash Player on Windows Home Server:

1. Open Internet Explorer.
2. Click Tools, and then click Internet Options.
3. Select the Security page.
4. Click on Trusted sites.
5. Click Sites.
6. Add http://*.adobe.com and http://*.macromedia.com as trusted sites, and then click Close.
7. Click OK to close the Internet Options window .
8. Open http://www.adobe.com/flashplayer and let it install.