Upgrade android version for dell streak locked phone

Hi,

A friend passed me over her old Dell streak phone (which seems to be locked if it makes any difference according to the unlocker program - not that I dont have access to something or some error message)

It is currently android version 1.6 and i want to upload it in order to be able to download whatsapp and all these sort of apps.

please can someone help me on this? By going to settings and checking software actualizations it tells me there is no new software available...

I know it is old model and android version but it willl be very helpfull if you could help!

Thanks in advance