A few suggestions (I have never configured Tomcat directly on Windows, so I'm talking from a Linux perspective):
Does your C:\Tomcat\conf\server.xml contain an entry for localhost at port 8080, and does that entry reference C:\Tomcat\webapps as its appRoot or docRoot? I doubt this is problem because you are getting a 404, so it is definitely connecting.
Remove the / from the end of your URL, it should end with /form.html
Do you have a /WEB-INF/web.xml relative to your application? If not, you will require one with earlier versions of Tomcat. As of Java EE 5 (the new version), you don't actually require it, but its use was mandated for all (even static) applications prior to EE 5.
See if that helps.
Charles Lyons (SCJP 1.4, April 2003; SCJP 5, Dec 2006; SCWCD 1.4b, April 2004)
Author of OCEJWCD Study Companion for Oracle Exam 1Z0-899 (ISBN 0955160340 / AmazonAmazon UK )