error with host file

[patrickv]

Each time i restart my coworkers pc the host file damages.the host file is 1kb in size but when it damages, it's 2kb.
here in the office we use AS400 client access to connect to the system.
if the host file is damage, i get the "winsock error" in AS400.
so i replace the host file with another one from another pc ,restart AS400 and it connects. but if i shutdown the pc and reboot the host file goes haywire. it looses all info in it and becomes a normal text file.

this pc has no viruses ,am sure, and it's just been from a format for 1month.

so what can be doing this ?

i tried to repair windows but it work work

 

[patrickv]

it's ok now, i called upon an AS400 expert.
he made the connection bypass the host file.
(and i freaking out back here)