Hacked everytime I install wordpress

I was hacked for the first time in December. Now I asked my host company to delete everything that was on my cpanel and I started from scratch. I have lost count of how many times I have tried to install wordpress on my cpanel. I manage to install it. I then start creating my blog. everything is all fine until I log out. when I try to lob on again, it does not recognise my username and password…Please help!!!