how to install <Preempt-RT kernel> on top of Wheezy

Would be tricky to remove the other 3. If you haven't done that before. I would highly suggest that while you have a backup of your current config that you remove them now. I can tell you that I have ran into the issue of I'll do it later .... then later arrives and I didn't have a backup config... lost all my changes lol

My suggestion would be to wipe the hdd clean and do another install without any other os's that you didn't want. It may eventually bother you enough to remove it later... where more damage can occur!

If you would like to attempt to remove the distro's you can do that in the installation dvd. When gparted comes up you can remove the other partitions. You will then have to update grub to remove the entries.

Ok thanks but how do I wipe the hdd clean in linux (I can do it in windows but do not know how to do it in linux)?

ok thanks

I am installing Debian 7 Wheezy - default choice is always " guided partitioning > guided - use entire disk", and following these default choices is precisely what leaves me with a list of 4 operating systems that I have loaded, with the most recent (correct) version at the top which is selected automatically. Searching Linux sites , strangely there is no way to do a clean install of Debian that wipes existing installs in the process

Anyway now I have started for the 3rd time, it warns me when I click "abort the installation" that "your system may be left in an unusable state", so it looks like now I am going to end up with 6 operating systems rather than 4 !! Frankly I can see why Linux is a pain and i am beginning to regret getting involved. Luckily my drive is 250gb so I think it has space for plenty of duplicated installations

Stop the install and don't use guided install.

Delete the partitions and start the install over. Only use the install for gparted. Or use a windows boot disk and remove all the partitions.
That might be simpler for you since you do not yet have the experience.

www.debian.org/releases/wheezy/amd64/ch0...html.en#partman-auto

6.3.3.2. Guided Partitioning
6.3.3.3. Manual Partitioning

In later versions of Linux such as Linux mint things are much simpler and just work.





In this video at 2:00 min is how you need to format your hard disk. It will remove all partitions from the drive, and alow you to set them up how you wish. or you could remove the partitions and write changes to disk. Then reboot and start the install over again and use the guided partition setup. That will give you one install only.

Thanks. Well I aborted the installation and seems no problem at all. Maybe I do not really have 4 OS - it does list 4 boot up lines of which it automatically chooses the top (most recent without Root password). These are exactly as follows:
Debian GNU/Linux, with Linux 3.2.0-4-rt-amd64
Debian GNU/Linux, with Linux 3.2.0-4-rt-amd64 (recovery mode)
Debian GNU/Linux, with Linux 3.2.0-4-amd64
Debian GNU/Linux, with Linux 3.2.0-4-amd64 (recovery mode)

By the way thanks for the offer of phone conversation support - very kind but unfortunately i am in the UK so not very economic to talk to the US.

Any particular reason you are using such an old linuxcnc distro? Have you tried any other distro's?

Thankyou so much for a great video !!!