I can't fix the latency in Cubase LE 5. Please Help. Thx

I am a newbie. However, I have researched and put time into learning Cubase LE 5 for beginners. I am using Alesis i02 express interface as well. I am able to record with a mic, guitar and record my external keyboard using a MIDI cable. The issue I’m having is hearing the audio/keyboard notes a half a second or so behind touching the keys. I have tried using advice from youtube videos, but no luck in fixing it. I downloaded ASIO4ALL and there’s little to no difference. Please, if anyone can help me resolve this headache, I will be much appreciative.

I use cubase 8.5 artist and have the i02 express too and are faced with the same problem also i connect the i02 through asio4all v2 but hear nothing when i press a piano key

Please Help