How to run Windows under VirtualBox on Fedora Core

Recently I needed to install Windows XP under VirtualBox on my Fedora Core 9 mashine.

After a successfull VirtualBox installation, I got an error when trying to install Windows from .iso image:

VirtualBox can’t operate in VMX root mode. Please disable the KVM kernel extension, recompile your kernel and reboot (VERR_VMX_IN_VMX_ROOT_MODE).

The error message means your kernel has loaded kvm module which conflicts with VirtualBox.

How to fix the problem?
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How to run Internet Explorer under Linux

If you do web development you may want to test your web applications under IE.

In case you work under Linux you have a few options for this:
a) have another machine with Windows installed
b) have Windows installed on the same machine and reboot each time you need to perform some testing (don’t forget a need to run web server under Windows too or upload your changes to a live server)
c) have Windows installed on the same machine and try to launch IE using wine
d) use IEs4Linux

As for me – option a) isn’t convenient (and requires additional computer involved), b) is very time-consuming, c) is too hard task and also requires a time to get all working (if it will work at all). I found that option d) fits my needs of quick testing in the best way: IEs4Linux – is a tool which installs a lightweight IE package on your Linux system (as I understand this is a variation of the option C) – they even offer a few versions of IE. The package is installed quite fast and easy even for me – not an admin person.

Well, it may glitch sometimes (as IE does in general), but what you get is pretty enough to check some JS/HTML.

Two words about CAPTCHA

I like nice looking CAPTCHA images like this one:

nice captcha

and don’t like ugly ones like this:

ugly captcha example

I call the first image “Google style CAPTCHA”. The second – “ugly letters”.

It’s hard to break “Google style CAPTCHA” (depends on distortion level), most “ugly letters” used with the standard software (forums, etc) can be broken quite easy.

Due to it’s visual specific “Google style CAPTCHA” matches most designs, “ugly letters” makes a page looking at least not professional (as for me).

I was looking for a tool to create “Google style CAPTCHA” or at least for algorithm which describes such distortion and found a perfect tool: KCAPTCHA.

Hint: You may click this link and see how KCAPTCHA works, obviously text will change with every reload.

It allows to setup CAPTCHA colors, has characters settings and also provides some distortion settings.

I found the KCAPTCHA fits all my requirements, it is going to be modified a bit and be used whithin my Cake app :)

The KCAPTCHA site also contains some interesting info about CAPTCHA creation approaches and breaking.