Any key press goes to line end while typing

Question

When I click any key my Acer Aspire 4736z win7 goes to end of that line.

Even if I select a word and start to replace it another, courser goes to line end after the first key up.

Is it a virus or any system fault? I had done a system check and system scan using avast.

I cannot use short cut keys and so on. I don't know what this is?

Answer 1

OP answers question in comments. The issue was a faulty keyboard