dual boot - How to install ubuntu on already existing partitions

I installed Ubuntu 32bit because I'm a noob and now I've uninstalled it to install the 64bit version.

After uninstalling I'm left with two new partitions a 80GB and a 26GB from the previous automatic dual-boot installation.

1. Are these partition sizes OK?


2. How do I manually install 64bit Ubuntu on these two partitions? Please tell tell me in detail what to put in "Use as:" (ext4 or something else?) and what sort of end to put: / or /home or /boot. On which partition.

I am sure these partition are OK. It will be better to create an additional partition (that has the size of your RAM) by shrinking one of these partition so as to use that as the swap partition. You can use the remaining two partitions for / and /home. If you wish you can create another partition (which is 500MB-1GB) for /boot. Refer the documentation to know more.

At the time of installation (from live USB/CD), select something else as the installation type and specify the mounts points for each of /, /home (and if you indeed create the other two partition- forswap and /boot). Refer this thread.