Is it safe or not

Learn about Computer Security General Security Questions and Comments
#1

In a wireless network, windows7’s 139, 445,137 are all default open, every user account have a password, no firewall installed.
is it very easy for other to take control of my computer in the same network?
if so, what about those school and other institution’s network, they all have the same problem.
It is ______ to take control of my computer in the same network.

  1. very easy (using what kind method)
  2. very difficult
  3. nearly impossible
#2

Preventing an untrusted party to access somebody else network would be the first step to consider and it is not unlikely there are security policies for all trusted parties to follow (I assume that methods to not compromise a network are likely to be mentioned)

Even a password provide no security if written on a post-it and stickied on the monitor. Nor even a supposedly unknown password provide any protection if it can be easily guessed in reasonable amount of time.

I’m no expert but I guess there is no single answer to such question. Penetration testing is used to evaluate specific scenarios as part of a security audit.

If you find a legitimate forum meant for related security researchers (but also open to general pubic) which address these aspects in an ethical and responsible way please let me know. :-TU

#3
is it very easy for other to take control of my computer in the same network?
It all comes down to their skills and time
if so, what about those school and other institution's network, they all have the same problem.
If their is a problem , they'll just check their "logs" to see who did what. If you do something to someone elses computer, the administer (or who ever is in charge of the network) is going to know. (that includes any programs you installed or used)