If you want to get back a list of all currently installed software,
dpkg helps. I assume that you can still access your old harddrive. So at a working Ubuntu system you can enter
dpkg --get-selections to get a list of all currently installed software. In your case you have to modify this a bit:
- Use a live CD or another Linux system.
- Mount your old harddrive (
mount /dev/sdX1 /media/sdX1 where
X is the letter for your drive)
Open a terminal and enter
dpkg -root=/media/sdX1 --get-selections > installed-software.txt
X above should be the correct letter where your drive is mounted.
dpkg opens the file
/media/sdX1/var/lib/dpkg/status and reads informations about currently installed software. This will be written to the file
installed-software.txt. Now save this file to a USB stick or some other media.
Now you can install a new Ubuntu system. When this is finished and rebooted, open a terminal and enter:
dpkg --set-selections < installed-software.txt
apt-get -u dselect-upgrade
Now all software from your old system is selected and will be installed to your new system.