Problem

We just got some new laptops in at the office.  I’m now going to be running Vista 64 bit with 8 GB of RAM.  I need to move my files over from my old laptop to my new laptop.

I have some nice external drives hooked up to my home pc.  Since my home pc, my old work laptop and my new work laptop are all on the home network I figured I would just transfer the files using the external drives hooked up to my home pc.

Suddenly today I could no longer connect to the shared folders on my XP box.  Windows Vista on both the old and new laptop kept giving me errors:

It was working a few days ago.  In fact if I use my wife's PC, which is windows XP, everything works fine.

So I did some searching, found the solution and figured I put it here in case someone else runs into this.

Solution

Apparently XP uses an older mechanism to communicate than Vista.  So we need to make sure Vista will ‘allow’ itself to communicate via this old mechanism if appropriate.

We need to crack open the local security policy in Vista – type ‘local’ into your vista start bar to find it and launch it:

Once you are in the local security policy window, drill into Local Policies, click on Security Options and then find ‘Network security: LAN Manager authentication level’ in the policy list:

Notice how mine was set to ‘Send NTLMv2 response only’.  Well I guess XP uses old NTLM and we need Vista to communicate that way if necessary.  So switch the setting to ‘Send LM & NTLM – use NTLMv2 session security if negotiated’ and click ok.

I have a suspicion that this was working until I went into the office Friday and hooked up to the work domain and a new, stricter policy was forced down upon me.

Anyway – just in case it happens to you.  There you have it.  Now I can copy gigs of data to the external drive and move em to the new laptop.