Old Larry wrote: "Another bad thing of Steam is the login method : Every time when I want to login on steam, I must wait for a code in my e-mail, and this is very frustrating. "
If you save the computer when logging in then you won't have to do this every time and it will save your credentials on the PC you logged in with. Depending on where you log in from there will be a box that tells you to give the computer/browser a "Friendly Name"
If that is for some reason not working, open up Steam settings and make sure this is unchecked:
Alternatively, although
NOT recommended (Steam requires this feature for some things like trading, not to mention you're safer when using this) you could turn Steam Guard off