How to Perform a Clean Install of Windows 8 with an Upgrade Disc

Tested, tried and TRUE! I bought a Windows 8 Pro Upgrade a couple of systems back but never ended up using it. Now, I built a brand new system that I want to get Windows 10 on so I needed to use this upgrade.

If you’ve already formatted your drive or you’re moving to a new hard drive, you are not able to perform a “clean install” without installing an older version of Windows first. You are allowed to install Windows 8 cleanly, but when you go to activate, you get an error 0x8007007B saying your product key can only be used for upgrading.

If you get that error, here’s how to fix it:

1. Press the Windows key and type regedit
2. Press enter to open the Registry Editor
3. Navigate to HKEY_LOCAL_MACHINE/Software/Microsoft/Windows/CurrentVersion/Setup/OOBE/ and double-click on the MediabootInstall key in the right pane
4. Change the key’s value from 1 to 0
5. Exit the Registry Editor
6. Press the Windows key again, and type cmd
7. Right-click on the Command Prompt icon and run it as an administrator
8. Type slmgr /rearm and press Enter
9. Reboot Windows

When you get back into Windows, you should be able Activate Windows as normal without getting an error. You could use this trick for evil but it is not recommended or encouraged.


Rename Root Volume Group (VG) on Linux Server

This walk-through worked on a virtual server running RHEL 6.7 in a VMware environment.

As I rebuilt an existing VMware guest that was being scheduled to go into production, I realized I did not rename the default volume group from vg_hostname to rootvg.

You must be root user and it is extremely important to backup the files below. It’s also important to know how to boot up in rescue mode with other boot media in the event there was a typo or other unforeseen issue.

Backup fstab file

cp /etc/fstab /etc/fstab.orig

Backup grub.conf file

cp /boot/grub/grub.conf /boot/grub/grub.conf.orig

Rename volume group

vgrename /dev/vg_OLDname /dev/rootvg

Change all instances of the old volume group in the following files:
Edit /etc/grub.conf (which is a symbolic link to /boot/grub/grub.conf)

vim /etc/grub.conf

Search and replace


Edit fstab file

vim /etc/fstab

Search and replace


Move boot image

mv /boot/initramfs-$(uname -r).img /boot/initramfs-$(uname -r).img.backup
dracut -v /boot/initramfs-$(uname -r).img $(uname -r)

Verify your work

If your system comes back up, you are golden. If it does not…


Get Process Count on Linux

The first part is to identify the PPID. I used this command to get my PPID for the mysql user:

# ps -A -mPl | grep mysql


I then used this command to get the total count for all child processes for the given PPID for the mysql user:

# ps -elm|grep 902|grep -v grep |wc -l




If you want to get a count of ALL processes, use the following command:

#  ps -elm|wc -l




Kevin is putting a script together that will collect these counts periodically. One of us will post it to the article when tested and complete.