IE behaviror when opening html file on hard drive

I'm doing some work with web page development. If I open Firefox and then go to File, Open File, browse to a file on my hard drive and select it, it opens in that tab. That's good.

But, with IE 7, if I try the same thing via File, Open ..., it displays a message panel saying IE needs to open a new window to display this webpage. I attached an image of the message.

Is there a setting in IE I can change to put a stop to this annoyance? I've looked but haven't found it yet.

 

You should try resetting IE. Tools -> Internet -> Advanced. By the way: IE8 is far more safe and could perhaps solve the problem?

 

Well, I discovered the setting that causes this behavior. And, it's unigue to IE 7 running under Windows Vista. I realized this when I tested the procedure in IE 7 on my Win XP computer and the file displayed directly in the same browser window and tab.

The reason for the behavior is this: In Windows Vista, Internet Explorer 7 runs in Protected Mode. So, IE 7 is more secure with Vista than with Win XP.

I can disable Protected Mode in IE 7 in Vista and then IE displays the HTML file from my hard drive directly in the same browser window and tab. When Protected Mode is turned off, IE displays a warning in a bar immediately below the tab(s).

I may update IE in my Vista computer but I might postpone that awhile longer. I use Firefox most of the time but, as stated in my original post, was testing web pages in IE to see whether they appear the same as in Firefox. I don't believe many Internet users in the general population are using IE 8 yet.

On the other hand, I may update IE in my Vista computer to version 8 soon since I could still test pages in IE 7 on my Win XP machine (which also has Firefox installed).