I know the second box is, err I mean the second picture..
Login
Password
The small box is remember password.
Left wide box is login
Right one is cancel?
Then the two boxes below,
The top is register?
Bottom is forgetting your password.
theres an issue with your windows and how it is displaying text.
Do you have any programs that modify the look of windows?
If not, I suggest running some scans and seeing if anything is screwing it up.
But basically, this is most likely not an issue with steam, but with windows.