I now cannot connect to the internet (wireless option is not even showing as available in network connections) and next to ethernet in devices there is a yellow question mark and exclamtion mark next to it.
You need definitely the WLan driver.
Here you will find all Wlan drivers:
http://aps2.toshiba-tro.de/wlan/
Sorry but there are many Equium A100 models and therefore it’s not possible to say what WLan driver you have without knowing the model number….