Problems with installing woocommerce ?!

Hi

Im not sure why that happens to you, but this might help you for now, to do a manuel installation:
https://www.ads-software.com/plugins/woocommerce/developers/
https://downloads.www.ads-software.com/plugin/woocommerce.2.5.2.zip

else i suggest wait for dev to respond or:
https://www.google.dk/search?q=Failed+to+write+file+to+disk+wordpress

i tried to instal manualy but stil dont work. it says :Failed to write file to disk.

It sounds like you plugin directory is not writable. Install manually using FTP.

https://codex.www.ads-software.com/Managing_Plugins#Manual_Plugin_Installation

i tried to instal wp file manager so i can do this manually .. but it says same thing as for woocommerce plugin : Download failed. Failed to write request to temporary file.

Thats still not using FTP directly.