Re: delete partitions without reinstalling
Unless Ubuntu is on the first partition (/dev/sda1), if you remove non-used partitions, you will change the partition numbers.
Depending on how the partitions are identified in /etc/fstab, after the partition numbers are changed you might not be able to boot. If it uses "boot by-uuid", then it could be OK.
If you post the /etc/fstab file, we can answer that question.
Intel Core i7-950 / Asus P6X58D-E / Nvidia GTX480 / siduction 64-bit on OCZ Revodrive SSD / KDE4.10.2/ Kubuntu 13.04