Network between 7 and XP lost?

I had a network set up between my Win 7 machine and a XP box, and was sharing whole HDD's ie M:/ D:/ and F:/ these are all data areas and not where either operating systems live. I had this set up using (Workgroups) on both machine and was able to read / write across machines in either direction with no problems.

Then after a while of use, I find first the one direction was blocked , now both are lost???? and I can't even "PING" my other machine?

Win 7 sees only ONE machine? itsself, on the network? from the XP end I get the two icons for the two machines, however clicking on the Win 7 machine brings back "Access Denied"

I have tried reseting my router to no avail, anybody know why this has just started to happen, and I didn't do or change anything?

Oh wow..I just posted almost the exact same message...see mine:

Connection lost between Win7 and WinXP

It might be worth checking under Advanced Sharing settings to see if anything changed. Those two Windows need to look like the pictures below.

Try checking your firewall.

I have those settings and my firewall is down. Doesn't fix it.

Yes the same, I turned off Firewall and Anti Virus to no evail.

Funny thing is I can't even "Ping" my other machine, so something serious is blocking the traffic, although internet access is uneffected???

And I bet if you reboot your win7 machine, all is fine right?

Sounds like the firewall is still blocking access to me. Once you toss a firewall and A/V into the mix problems will surely follow. Be suspecious of your A/V and firewall for they are surely the problem.

did you install / uninstall anything prior to this issue? It could be a windows update that turned certain settings back 'on' automatically. simple file sharing turned off on your windows xp box? Same workgroup? ex: WORKGROUP Try sharing a single folder instead of entire drive? I'm not sure if you were attempting to access the "drive" by: \\computername\c$ or if you actually "shared" the drive itself (not secure btw)

This gets even more strange by the minute with no explaination I can think of?

I tried turning off the Norton Fire Wall and the Anti Virus - no joy

I tried Rebooting the router and ALL machines - No joy

Then

Turned off Win 7 machine and I simply un-pluged my network cable for 15 seconds, and reconected it....... re booted and ........

Working now ??????

Yes I share each "data" drive which contains my structured folders for Music, Photos, Videos and the like --- Thats the way I like to do it so its looks the same which ever machine I open them up on?

No keen on these Windows 7 Libraries, although I now also find those as well now listed on my XP box

Is there a way I can un-share those, but keep my shared drives?

Paul