W900i startup. Pressing & holding c won't work!

hey, I got this W900i phone and, yeah, I know this phone is, like, 6 years ago, but, and,yeah, i just got it about a year ago.
I just got irritated by the message memory being full and crap. So, i searched the internet on how to increase the sms capacity. I just found this post on editing the system on the phone.. and, well, this is where my problem starts.

Everything about opening the phone's system says things about pressing "c" and holding while plugging to the pc. When I do so, nothing happens. The phone only turns on immediately when i do so and goes to file transfer mode. I'm just so irritated and tired of this. Can anyone help?

Replies much appreciated!

BTW, I used XS++, far manager, setool2, setool2 lite, and, i guess that's it.
Anyway, I think the problem itself is within the phone going to file transfer mode everytime.

Try it,
Turn off the phone ,reinsert battery, hold "c" or 2 + 5 , and connect phone to the pc, release "C" or 2+5 until SEMC pop up appear in pc. CMIIW