I had an issue using PuTTY (free Windows SSH client) this afternoon when trying to login to a work server. The error message seemed very odd:

Unable to open connection to andrewbevitt.com
gethostbyname: unknown error

OR BY IP ADDRESS

Unable to open connection to 220.233.157.156
Network error: Invalid argument

Turns out that it’s a Windows 7 feature. I had the PuTTY executable sitting on my Desktop as part of my domain account so apparently something executed out of $HOMEDIR\* gets limited.

Solution: Copy the executable to a local disk partition.