as I had said in an earlier post, in Internet Options under the Programs Tab, first block, it says to not use IE 64 bit as the default browser, in both Vista and Win7. I think a lot of sites are not geared up for the 64 bit Browser and won't open if you are using it.
The reason it suggests not to use a 64-bit OS is simple- most content plugins don't run on 64-bit. Specifically, of course, Adobe Flash. Since IE 64-bit is a 64-bit application, it can only link to 64-bit DLLs. Therefore, all plugins will need to be 64-bit. Most other plugin vendors have done rather well and have released 64-bit versions. Adobe is the holdout.
The flash problem isn't limited to IE 64-bit. Minefield (a 64-bit build of Firefox) cannot run flash either, for the very same reasons.
the dialog states that "IE 64-bit cannot be set as the default browser". This isn't a case of "can't" as much as it is a case of "won't". The reason was an actual conscious decision not to make it possible to set it as the default browser, for the very reasons I noted previously- that is, lack of support for popular plugins. The only time a site will have trouble is if it uses flash or another unavailable plugin. a website doesn't need to be written specifically for 64-bit. It's fully possible to run 16-bit browsers and still navigate the web fine. after all, it's just a few files and scripts; the bitness of the interpreters of that markup and script is largely redundant.
Q: Why isn't 64bit IE the default browser? Why can't I set the 64bit version of IE as the default browser?
A: This was an explicit choice made by the IE team, which may change at some point in the future. The problem is that users might inadvertently get "stuck" using the 64bit version and not realize it. This might cause some problems.
Q: Why? What does not work properly with 64bit IE?
A: Browser addons, including BHOs, Toolbars, and ActiveX controls, must generally be the same bitness as IE itself. So, if you are running a 64bit version of IE, any site that uses, say, Adobe Flash, isn't going to work until you install the 64bit version of the addon. Sadly, almost no browser addons are currently available in 64bit versions, although that's somewhat likely to change in the future as 64bit Windows becomes more prevalent.
Q: So, is there any benefit to using 64bit IE?
A: Some users like to use 64bit IE from time to time for a variety of reasons, but in my opinion, none of them are super-compelling. Here are a few reasons I've heard:
* DEP/NX is always on for 64bit processes. (Of course, on Vista SP1+, 32 bit IE8 has DEP/NX enabled by default too.)
* It crashes less. (Because most addons don't load in 64bit IE, it tends to be more reliable.)
* It's faster. (Mostly because most addons aren't loaded. There's also an unsubstantiated claim that image decoding is faster, but I find this very unlikely).
Q: Okay, so why offer 64bit IE at all?
Because we have to. :-)
One thing to keep in mind is that Internet Explorer is basically the combination of a number of platform components, including the networking components (URLMon/WinINET), the rendering components (MSHTML), the script engines (JScript.dll, vbscript.dll) and a variety of other pieces that hold it all together. These components must be made available in 64bit versions so that 64bit applications can be built using these components. Additionally, because Internet Explorer can be launched/created/used as a COM Server, we offer a 64bit version to enable hosting inside 64bit processes.
While we could have done work to make it harder for users to get to 64bit IE (e.g. by not creating a Start menu shortcut), I don't think there's any super-compelling reason to do so.
One day, 64bit IE might see a lot more use, as 64bit systems take over and 64bit add-ons become available. Time will tell.
So, the summary is this:
the downside of using 64-bit IE is that fewer addons and toolbars and so forth can run. The upside of this is that fewer addons and toolbars and so forth can run.
