Should I install IE9 (Internet Explorer version 9)?

IE9 works fine. IE9 causes problems.

I regularly hear from both sides of this argument.

For example, I've upgraded several machines to IE9 without a single hiccup. It was working, it is working, and life goes on.

On the other hand, I do hear from people who upgrade to IE9 and experience all sorts of odd problems and downright failures - not only in IE, but in technically unrelated programs, such as their mail program.

So in the face of those kinds of conflicting reports, it's hard to make a blanket recommendation at this time.

Instead, I'll make three.

Install IE9

If you are setting up a new machine, have just received a new machine, or are reinstalling Windows Vista or 7, then my take is this: go for it.

IE9 seems to do best when the system that you're putting it on is relatively clean. It should not have a lot of software installs nor multiple years of patches. It should just be fundamentally stable from the start.

IE9 will take advantage of some hardware acceleration that IE8 and prior versions don't, and could provide you with a generally faster, better, cooler web experience. Being the latest version of IE at this writing, it'll also be the version that will be supported more completely and for a longer time than any other.

There are some UI changes that confuse people at times, but by and large, when it works, IE9 works well.

And a clean machine gives you the best chance that it will.

Don't install IE9

First, if you're running Windows XP, this is your only option. IE9 is not available for Windows XP.

It might be wise to avoid IE9 if your machine had Windows Vista or 7 installed years ago or if it has been through only upgrades, service packs or Windows Updates for all that time. It might also be wise to skip IE9 if you've been regularly installing and uninstalling lots of different software.

If you had a malware infection that you "cleaned up" without reinstalling Windows, I'd also hesitate with IE9. Even when removed, malware often leaves traces that can impact other software, and in particular, Internet Explorer. That's one of the reasons why I often say that the only way to be sure that malware has been completely removed is to reinstall.

Now, none of this is to say that these are the only predictors of IE9 problems - or that they even guarantee that you will have a problem. It's a matter of probability and these are the types of things that stack the deck against a successful upgrade.

If you're really itching to get IE9, but your machine is kind of a mess, it might be a good excuse to do that backup, reformat, and reinstall. That's something that many folks, including myself, feel is just a good idea to do periodically anyway.

Install IE9 but...

In all honesty, most people aren't at either extreme. Machines are used "some", they're not pristine, but neither are they a horrible mess.

That makes the decision harder.

So, I'll put it this way:

• There's nothing that says you must upgrade to IE9, yet. If IE8 is working and working well, why tempt fate? As the old saying goes, "if it ain't broke, don't fix it."

• If you do want to upgrade, take a full system image backup first. There's nothing at all wrong with upgrading and, for many if not most, it'll just work. But in case your machine happens to be one on which IE9 will have problems on, there's nothing quite like a full system backup to make it all go away. (Though you can try uninstalling first.)

IE9 works for most people. Honestly, I think it's a fairly safe upgrade, but I hear of enough problems from people that it's clear that approaching IE9 with some caution is wise. As we've seen, waiting is an option, but so is simply making sure that you can revert back to IE8 if you encounter issues.