Dapper Drake to Hardy Heron replacement

As a Ubuntu newby I'd like to replace my Dapper version on a dual boot laptop running XP home with HH 8.04. I downloaded 8.04 to a live disk and it runs ok but I I'm unable to install it over the old version. I think I need to delete the old version in its partition first to free up space. One problem is I don't have an XP CD. I don't want to change the boot loader or repartition the HD, just swap versions of Ubuntu. Other posting I've found require an XP CD . Any help will be appreciated.

You need to be careful as you could lose your data here. Make backs ups and then boot into Ubuntu 6.06 and do the following:

sudo apt-get dist-upgrade

This should upgrade you to 8.04 LTS.

You did not need to download the .iso image, but keep it in case things go wrong. Again: Back up your data; fail to prepare, prepare to fail.

Why not go all the way to the newest version 9.04?

I chose to go to 8.06 vs. 9 because I thought, perhaps mistakenly, that 8 has support for that version out into '11, vs a shorter support for 9. I tried the update command from terminal and all seemed to go well. After an hour and fifteen minutes a restart of system was asked. When I did this, boot was still into 6.06, no sign of 8.06. ????