[ubuntu-uk] how to change hdd/partition numbering

[Vitorio Okio]

I've deleted with GParted unwanted Dell Utility partition sited the first 
on my HDD.  This partition was set as /dev/sda1, so all others followed 
correspondignly: /dev/sda2, /dev/sda3, etc.

Now after deleting and booting back in Ubuntu my now first partition is 
still marked as /dev/sda2. And all others follow.

How can I change this?  I would like my first partition being set /dev/
sda1, etc.?

Thank you.