So let’s assume that you read up on dual booting, chose a second operating system that extended your computing capabilities, and pulled the trigger. Congratulations! Your system now has the potential to carry you much further, and your software options are incredible. You spend some time enjoying the new operating system, customizing it, choosing new programs, and after some time, decide you want to hop back onto your old system. You close everything up, tell your system to reboot and… it jumps right back into the new operating system without asking where you wanted it to go.

This frustrating scenario is not at all unfamiliar to those who decide to dual boot. Fortunately, there is a solution for nearly every possible configuration and installation order between Windows and Linux versions and distributions. This how-to will help you get the bootmenu for each possible option back, giving you access to the original operating system if it is accidentally blocked out by the second OS.

The process does require you to have a physical copy of an installation disk for whichever operating system you are trying to get access to. If you installed Ubuntu as your second operating system and it blocked you from Vista, you need a Vista disk. If, for some reason, you installed XP and lost Ubuntu, you will need an Ubuntu installation disk for the specific release you are trying to get to.

Also, this how-to looks specifically at how to restore access to Ubuntu and may not be universally applicable to Linux distributions. It should, however, serve as a solid starting point, and many other distros follow the same process.

The most common scenario, restoring Windows Vista or 7, is one of the easiest. Run the installation CD at startup, and after the location options select Repair Your Computer. Unselect your installation if the system locates it, and then open Command Prompt. Type in:

bootrec.exe /fixboot

Press enter, then type:

bootrec.exe /fixmbr

Close all windows, do a restart, and your Vista/7 bootloader should appear.

Those restoring XP have it even easier. Insert the install CD, allow it to proceed, then type r when it asks if you are repairing rather than installing. This brings up a command line, in which you should type, pressing enter between lines:

fixboot
fixmbr
exit

Finally, those restoring Ubuntu or a similar Linux system need to start by identifying the drive their system is installed on. From the terminal on an install disk, type:

From the information that this calls, identify the drive that holds the Linux system, such as /dev/sda2. Next, substituting in your own drive in place of sda2:

sudo mkdir /media/sda2
sudo mount /dev/sda2 /media/sda2
sudo grub-install –root-director=/media/sda2 /dev/sda

While not comprehensive enough to cover absolutely every possible configuration you may have, these simple steps can help most people get back their original bootloader. If you follow these steps and find you lose the loader from the second operating system, just follow the same steps for the second. Good luck!

I actually knew several methods on how to fix the MBR (Master Boot Record) to get rid of the Linux bootloader. There was however only one way that would safely fix the MBR and remove the Linux bootloader from it. I’m saying safely because it can happen that methods such as Fdisk /mbr would require a reactivation of the Windows operating system.

MBR Fix is a small command line freeware for Windows that makes it possible to fix the Master Boot Record from the command line of your operating system. Just download the tool, open the command line and type

MbrFix /drive 0 fixmbr /yes

to fix the MBR and remove the Linux bootloader.

There have been actually two announcements this year that bypass driver and code signing in Windows Vista which essentially means that DRM can by bypassed and unprotected HD content can be watched in HD quality on your computer. The first, which dates back to January this year was described by Alex Ionescu in his own blog.

This feature is the ability of the PMP to notify A/V applications that there are unsigned drivers on the system, as well as provide a list of unsigned drivers. The idea is that the application can either outright refuse to play content, or that it can scan for known anti-DRM drivers which might be attempting to hook onto the unencrypted stream. This leads me to believe that it’s up to applications, not the OS, to enforce this DRM check.

The great thing about the code I’ve written is that it does NOT use test signing mode and it does NOT load an unsigned driver into the system. Therefore, to any A/V application running, the system seems totally safe — when in fact, it’s not. Now, because I’m still booting with a special flag, it’s possible for Microsoft to patch the PMP and have it report that this flag is set, thereby disabling premium content. However, because I already have kernel-mode code running at this point, I can disable this flag in memory, and PMP will never know that it was enabled. Again, Microsoft could fight this by caching the value, or obfuscating it somewhere inside PMP’s kernel-mode code, but as long as it’s in kernel-mode, and I’ve got code in kernel-mode, I can patch it.

Alex fears an expensive law suite and ponders how he should publish his findings without being sued by the content owners. I think that this is one of the tactics that they use to enforce DRM. It has nothing to do with hardware or software, they put pressure on governments, software companies, hardware manufacturers and individuals. Fear is one of their strongest weapons. They apply the same tactics by suing a handful of individual file sharers and announce it widely on the world wide web. The hope is of course to create fear in others who will stop file sharing over p2p because of this.

NvLabs announced a bootloader called Vbootkit which they demonstrated on the Black Hat Conference in Amsterdam three days ago.

We have been recently researching on Vista. Meanwhile, our research for fun lead us to some important findings.Vista is still vulnerable to unsigned code execution.vbootkit is the name we have chosen ( V stands for Vista and boot kit is just a termed coined which is a kit which lets you doctor boot process).vbootkit concept presents how to insert arbitrary code into RC1 and RC2, thus effectively bypassing the famous Vista policy for allowing only digitally signed code to be loaded into kernel. The presented attack works using the custom boot sectors.Custom boot sector are modified boot sectors which hook booting process of the system & thus, gains control of the system.Meanwhile, the OS continues to boot and goes on with normal execution.

I think it is pretty interesting that everything that the content owners and companies like Microsoft throws at their enemies consumers will sooner or later be bypassed. The end result is that money and energy is wasted on protection that does not protect anything at all but merely annoys every single user on this planet.