Then make sure to deinstall the old SDK Tools and then install the new SDK (2.1rc2) (into the web directory of your local server) and the new CMD (126.96.36.199).
After that (if your local http server is running) you can launch the new docs (help) in the browser. Just type in http://localhost/sencha-touch-2.1.0-rc2 (if that is the name of your ST SDK folder). You should see the latest documentation. Go to the GUIDES which are on the 3. TAB and scroll down to the new Sencha CMD docs. For the beginning it is important that you read carefully the first TWO chapters. With that you should be able to create your first app and have it run locally in your browser.
If not, post here what doesn't work and I will try to help you out.
I got new SDK and CMD installed. Even I upgraded the JRE to 7.
I get some different error now.
"Unable to locate tools.jar. Expected to find it in C:\Program Files\Java\jre7\lib\tools.jar"
I dont see such files exists in JRE
D:\sencha\GS>dir C:\Program Files\Java\jre7\lib\tools.jar
The system cannot find the path specified.