I got this problem trying to build a new TCL from the latest download (4.7.7) to replace my 4.5.6.
I boot on the CD of 4.7.7 and it comes up with the correct boot screen but then loads the old system from the hard drive. My assumption was that I could boot on the new platform from CD, install cfdisk to clean off the partitions on the hard drive, and use tc-install and do a clean install.
I cannot clean of the hard drive partitions because umount says the the device is busy.
My hard drive is actually a 16GB CF card on an IDE adapter that plugs direct onto the motherboard so I cannot hot plug the card in after bootup.
Any suggestions how to overcome this.