Block complete network access for one local user

Question

Well, this is quite trivial question but I could not find a satisfactory answer even after trying many search queries both here and on Google.

I want to share my PC with my room-mate. And I don't want him to access ANY network(LAN included).
So, I can create an account for him and block network access for the same.
I would prefer avoiding any third-party tools as far as possible.
It's a simple home PC hooked up to a router for internet. No domain and other stuff.

(Technically, guest account can achieve this. But somehow, the guest account on my PC has network access!)

Answer 1

You can manage this via group policy settings: Start -> Run -> gpedit.msc

1. Create a new policy in GPMC by right-clicking your domain and pressing New. Name the policy No Internet.

2. Right-click No Internet and press Enforced to check it.

3. Select No Internet in the left-hand pane, select Authenticated Users under Security Filtering and press Remove, and OK to prevent the policy from applying.

4. Using Group Policy to implement Internet Explorer settings, navigate to User Configuration / Windows Settings / Internet Explorer Maintenance in the No Internet policy.

5. Right-click Internet Explorer Maintenance and press Preference Mode.

NOTE: If a policy is already defined, you must press Reset Browser Settings, which will reset any Internet Explorer Maintenance Group Policy, before you press Preference Mode.

3. Navigate through Connections and double-click Proxy Settings (Preference Mode).

4. Check Enable proxy Settings, Use the same proxy server for all addresses, and Do not use proxy server for local (intranet) addresses.

5. Type 127.0.0.1 into Address of proxy and 80 into Port.

6. Press OK.

7. Close the No Internet group Policy.

Tested this and it works. ( Source )