You should have the panel available from the window menu, to be sure you are checking the correct place I have added a screen shot to compare to.
If you do not have it here there may be a problem with the install. When you installed did you choose 'yes to all' when asked to overwrite any existing files? You should always choose yes to this.
Do you have a page open when you try to add the panel, you should try this as well.
If you do not get the panel no matter what you are trying there might be a corruption somewhere. The first thing to try is to clear the cache file if this is the case, the next thing to do would be to rename your config folder if clearing the cache does not work. Here are steps to take for both of these:
delete cache file