I use Allok 3GP to convert videos and put them on my phone, they work perfectly on my W800, but is there something different about W350i? At first W350i could be SIM Patched and now i cant even play videos on it. I tried 3GP & MP4 Format with video resolution set to 176x144 QCIF.

What do i need to do to play Videos on Sony Ericsson W350i? What screen resolution and format does it support?

for this questions i have a anwser it supports 3gp,mp4 like you have said in your postb and screen size 220x176 and below these numbers,
i think that i can open 320x240 screen resolution//my friend has the same phone.works perfect no problem...

it supports only 176x220 3gp format videos. Videos in format .mp4 play very slowly....i have a W350i thats why i know abt its video resolution....

or simply use alive media converter and convert videos to 3GP amr (as the option in that converter say)