Why Do I Get One-Way Traffic? Can only connect one way from one machine

I was wondering why I am getting the following problem:There are 2 PCs and 2 laptops in my home.All 4 machines run Windows 7 Ultimate, and all machines are in the same homegroup.However, when I try to connect to any machine but one from my laptop, I get the message "My credentials are invalid", in other words, it means I have used a wrong username or password.I am 100% sure the "credentials" are all correct, and are also entered correctly.Like I said before, i can connect to the other laptop, it is not even asking me for a username or password, probably because I set it in the past to remember the password.What is even more funny is the fact that the other machines can connect to my laptop without any problem.Like on my laptop, the other machines ask for a username and password, but after entering those, I get connected immediately.As far as I remember, the network is set up correctly, so I am wondering what is happening.I would like to try and take my laptop off the network and run the network wizard again, but the disabling of the network can be a bit fiddly in Windows 7.Has anyone got some advice (someone who recognises the problem or has experienced it him/herself), or someone who can advise me how to disable and re-enable the network with a minimum of fuss.Thank you.

Cheochi,Your post doesn't hold any relevance to the topic, your post quality has also not shown any improvement , thereby we will be proceeding to issue a ban.