I have a Sony Ericsson W580i and I have followed the instructions in Sony Ericsson support site to update to the last version of software. But when I run the Update Service application, choose my phone brand etc, when appears a message saying to turn off my phone and connect the USB cable pressing the C key, nothing happens. I remain pressing the C button and nothing happens. The instructions itself are somewhat confusing.
Is there a workaround here?
Any help will be apreciated.

Don't use SEUS, it can upgrade to CID53!

Go with XS++, or Setool2 lite. But you have to download the firmware to flash.

DONT USE SEUS!
It will update your phone to CID53 which is BAD
You will not be able to flash it or do anything to your phone once it is CID53
And no you cannot downgrade CID's
EDIT: Damt, 93bh, you beat me to it

Ive read this several places on this forum, But I just ran the SEUS last week on my debranded reflashed re everthinged w580i and I havnt had any problems... It just says that there arent any updates available.
The reason I downloaded and ran the update service was because I reformatted my laptop and that was the easiest way to get the drivers back so my laptop would regognise the phone.

Try removing your memory card if it wont connect, Mine wouldnt connect either...until I took the memory card out.