Is it possible to install without a CD or USB drive? [duplicate]

Solution 1:

Yep, all your friend needs to do is download and install Wubi. It's designed for this exact scenario. You can check it out here: http://wubi-installer.org/

Solution 2:

1. Use Windows 7 to shrink one of your partitions (you can shrink a mounted partition while running Windows). If you already have 4 primary partitions you'll need to remove one of them first.
2. Boot wubi and install GParted and create an extended partition in the free space you created, and then 2 logical partitions, one an ext4 partition large enough to contain your Wubi install, and optionally 1 swap partition (> size of RAM).
3. Migrate wubi to the partition, installing the grub bootloader at the same time
4. Boot the migrated Ubuntu and format the Windows partition, which you can then reuse as a separate /home or you can use the same migration script to move the migrated Ubuntu to it.

This solution doesn't require a live CD/USB (although it's always a good idea to have one.