With a 16MB video card and 384MB RAM anything like full screen video is going to struggle.
As you have asked, I won't mention upgrades....
i have a old computer, with only 16mb vid card......AMD 650 proc, with 384 ram. When i was using Win98SE sp2, i could play full screen, but now with XP PRO sp3, it will play in the normal screen that Youtube uses, but freezes when i try to play it Full screen. I did a forum search on my problem, and did not find anything to address my problem.......did the ADOBE Flash problem finding/fixing program. Is it freezing because i am stressing the Ram too much, and then should i be happy with just Youtube playing in its normal window?
Please, no suggestions to upgrade. I KNOW all that, but money is tite, so limping by for now.