Local network is trolling me

[Ceiling_Cat]

Is this the right place to ask? Anyway, I'm trying to connect two nearly identical computers (W7) in a network to share files and internet access (since buying a router would be a little too much for my needs).
When I try to connect though, the status says "Unidentified network. No internet access". Googled it for three days straight, seems to be "a wizard did it" kind of problem with no consistent solution. File sharing works, ICS does not.
Now, there's one problem - that shit worked before. It screwed up when I was trying to temporarily add a third computer to the network for a small LAN mayhem a few weeks ago. It's broken ever since.
I already:
- Played around with firewall
- Deleted route 0.0.0.0
- Checked without IPv6
- Checked for services causing this crap
- Checked for hardware faults, the cable and network cards are fine

I'm at loss here. Is there anything else I can do before I do a (most likely futile)reinstall?

 

[Toams]

well, if you're into non-conventional solutions that do half-assed work, you could try connectify.

 

[Toams]

it's like a bad ad-hoc network