multiple primary partitions

i bought xps 1645 about 2 mths back. HDD has three primary partitions

1: fat16 eisa configuration for dell diagnostics (hidden)

2: NTFS: dell factory recovery partition

3: NTFS: windows vista HP x64 (active & boot partition)

i have vista dvd &  driver& utilities disk. & all latest updates from dell website.

i am planning to install ubuntu & win 7 on two primary partitions and keeping the vista on the third partition & installing good boot manager for booting these oses.

is it possible to live without partitions of dell diagnostics and recovery? because i don't need them and i need two other primary partitions. i tried sun virtual box, but not satisfied with it.