Virtualization woes

A problem with virtualization that happens with legacy applications:

You start Explorer, you go in %ProgramFiles%\IDA\cfg to fix some configuration issues in ida.cfg. You double-click on ida.cfg file and edit it in your favorite text editor (let's say Notepad++). You save it. Start IDA. What? Why is the program still having the old behaviour? Did you mistype your last configuration change?

No!

Virtualization kicked in and your file was moved in a directory far far away. In fact, in %HOMEDRIVE%%HOMEPATH%\AppData\Local\VirtualStore\Program Files\IDA\cfg\. The problem was not IDA, it was Notepad++ that got virtualized. So be warned. If IDA had been virtualized too it would not be a problem.

Well at least I would not have noticed. However, imagine that IDA was virtualized. In addition, at first I used Notepad++ to modify the file, which created a virtual copy. Then I used standard Notepad to update it. I would have got an access denied. So I would have used the command "Run as admin". Then I'd get two different modifications from the base and IDA would continue to use the virtualized copy.

That is hypothetical, but it will happen. Just think about the registry virtualization. I hear all the weird problems support desks will face soon...

It should be noted that Microsoft knows this is a problem (1):

Although virtualization allows the overwhelming majority of pre-Windows Vista applications to run, it is a short-term fix and not a long-term solution.

For power users, I recommend disabling virtualization (1). That will reduce the number of surprises. Probably a lot of application will fail though, but only those that already needed administrative privilege anyway. If you were running as a user before, it should not affect you too much.

Watch out when disabling virtualization. If you've installed many programs where virtualization kicked in, you may get into troubles when disabling it. So you should disable it before installing third-party programs on your computer. I've warned you.

As the end note, don't get fooled, virtualization kicks in even when you are running as a standard user!

Reference
#1 "Understanding and Configuring User Account Control in Windows Vista"
http://technet2.microsoft.com/WindowsVista/en/library/00d04415-2b2f-422c-b70e-b18ff918c2811033.mspx
In you don't want to read the whole document, simply start gpedit.msc, go in Computer Configuration, Windows Settings, Security Settings, Local Policies, Security Options. There you'll see at the end the "User Account Control: ..." settings. (In French, it's "Contrôle de compte d'utilisateur", de isn't there for every settings, the translators didn't verify their translations.)