Vauxhall Astra power stering and speedo not working

this is an ongoing prob since the last time i was on here the p stearing just does not work at all as well as the speedo i have just started to fix the car after a few munths as i gave up with it for a while as it was doing my head in a bit i have other cars i was rebilding and playing with any way back to the probs speedo/ computer dionostic say l/h wheel sensor ie new hub this i have done as well as new cv joint when fited new parts should have speedo no not at all nothing but when started up car after fiting new parts power stearing was working until i turned car of then nothing at all just wondering does this need reseting though the computer like clering fault codes please help ;;;;;as i dont like to be beten by machines thanks budman