Try to remove weblogic from your hdd with eclipse settings or turn it off you'll need a couple free port numbers for example 8080, 8009, 8005 ofcourse it's depends by you, but if you wish work without troubles in the future my advice is as I wrote :D
after this one, download tomcat from:
http://tomcat.apache.org/download-70.cgi
version: 32-bit/64-bit Windows Service Installer (pgp, md5)
Install it in eclipse folder as TOMCAT7 and set up server in ecpipse environment this is the best way I know to have couple of tomcat (if you will have netbeans, eclipse maybe even a 3 or more instantiation and every one with different tomcat or other server to check it how it works)
I assume that you know some basics of setting up server if you dont know much about it dont be afraid to asking, cuz at the begining it can be a little confusing and sometimes annoying
and dont run 2 server at the same port at the same time - it cant work out
and btw you dont need to setting up any of classpath or system variables only follow as I told you
here you can check it out :
http://www.vogella.com/articles/EclipseWTP/article.html
you will need only to show the eclise the right path to your tomcat instalation (as I wrote make it in eclipse folder - it will remaind you it's not for remove or change :D)