When installing mandriva 2007 I choose the option to copy all the packages to my hard drive and now have a working oparating system. Now whenever I try to install additional packages the system hangs for ages and then tells me it's not possible.

Is there a way to make the package maneger look at the CD drive when installing packages instead of the HDD? or do I need to reinstall Linux?

Yes, you can, By going into the software installed and selecting "select where packages are installed from" or

something like that. here you may see the cdrom entry, but it may be un-checked, just re-check it. If not...

You should be able to put the cd in and wait a little while for it to spin-up, then follow the prompts after selecting "from cdrom".

Also, when the installer copies all the packages to your hard drive, you can find them in /var/ftp/pub

You may also do this with urpmi from the console like this....

urpmi.addmedia (put the name you want to call it here) file://var/ftp/pub/(name of the folder the files are in) with hdlist.cz

Mine looks like this,

urpmi.addmedia Mandy2007.0 file://var/ftp/pub/Mandy2007.0 with hdlist.cz

Hope this helps.