Windows 7 Explorer: Open in same window

I didn't find any sort of registry fix for this, but I did notice that if you use the hierarchy sidebar to change folders instead of clicking on the folder's icon, the new folder will open in the same window.

Edit: I apparently never posted the original topic. I was referring to a problem I was experiencing in Windows 7: Professional where I had set the folder options in Windows Explorer to open in the same window, but every time I opened a new folder, a new window would open to accommodate it.

Acrobat and Windows 7

I have been using Windows 7 professional for a couple of weeks now and I've noticed one particular problem with opening pdf files inside of Firefox. I have Firefox 3.5.3 but it is not installed on my Windows 7 partition. It is running off of my Windows XP partition. I have installed Adobe Acrobat Reader 9.1 as a plugin for Firefox but it will not open PDFs in the browser. I have to save to file and then open it with the standalone program. I'm not sure what the problem is.

Windows Powershell: Windows 7 Pro

Although I have only been learning about Windows 7 for a few weeks now, I have already stumbled upon an amazing new feature that comes packaged with the operating system. Although it has already been available for other Microsoft OS's, the second version of this tool has only been installed by default on Windows 7 and Server 2008. I am speaking of PowerShell. This scripting tool has more than I can think of what to do with. It seems that Microsoft has finally come up with a replacement for the old, weak batch scripting system. It also accepts a number of Unix commands, such as man, ls, cp, and mount. You can control processes from the server and manipulate the GUI, all in a command-line environment. Also, it uses a system of certificates and policies to determine which scripts should be allowed to run. An administrator can write a script and sign it themselves, but downloaded scripts or similarly suspicious scripts cannot run without being signed. It is a boon to Microsoft system administrators everywhere, but then, I'm sure you already knew that.