upgrade an old "kinda" broken ubuntu from a working lubuntu

i've been searching for this but i couldnt find an answer. (to state that i did search)

is it possible to update my ubuntu 11.04 from my current Lubuntu 13.10 ?

i have and "old" pc. specs are:
cpu: amd athlon xp @1.9
vga: ati radeon 9200 agp 8x
ram: 1 gb module - 1 module for 256 mb total: 1,25gb
motherboard: a7v8x-mx se

a few years ago i installed ubuntu 10.04, put a lot of important files there, and kinda "never used it again", i just used ubuntu once or twice in a year, when searching for old stuff.
my ubuntu was working fine, but i couldnt upload videos to youtube anymore. firefox just freeze and chrome crashes.
so i uninstaled chrome and i couldnt install it back, because my version was not supported anymore. so i started upgrading (it was quite difficult because im a begginer)
and i managed to upgrade to 11.04.

when trying to upgrade to 11.10, linux wont let me log in, the clock on the login screen works, but i cant move the mouse, cant use the keyboard and cant enter a terminal (with alt + f2) i read that it wont load up my video card drivers or maybe its the mouse and keyboard.

entering text mode allows me to perform console commands such as "sudo upgrade" , but since the LIST file is "broken" and i have to replace some lines to the "old-repository" it wont upgrade anymore, it will never find the files required.

i tried to install 12.04 but the install fails (like its some hardware problem).
tired of reading, i find that the problem is my old video card, so i moved into a "light" version of linux and here i am, it works just fine, even faster i think.

im in Lubuntu 13.10 and i love it, but i CANT use the flash player, only a few sites allow me to use the flash, i try with chrome and cant even run the chrome browser.

so im ok with that, but, is it possible to update my ubuntu 11.04 from my current Lubuntu 13.10 ?

11.04 ubuntu has 65 gb in a 80 gb ide hdd
so im afraid that i might run out of space soon in this 15gb filesystem.

the files i had are OK, i can access all of them from here, i just cant use flash.