I have three home machines, my main one can run Win 7 Home, Ubuntu 11.04 or Win XP Home, my spare runs XP Home and Ubuntu and my laptop runs Vista.  With the main machine running XP, the other machines can access the data drive.  But when I run Win 7 and they try to log on it keeps asking for user name and password.

With Win 7 Pro or Ultimate, changes can be made with the Group Policy Editor gpedit.msc.  But that isn't included in the Home editions.  I ran across a registry edit at www.tweaktown.com that fixes that.  The easiest way is to run this registry file.  Copy everything between the lines below and save it as an ASCII text file.  Just double-click it, then reboot.  As always, make sure you have backed up the registry before running this.

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Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa]
"everyoneincludesanonymous"=dword:00000001
"NoLmHash"=dword:00000000

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\LanmanServer\Parameters]
"restrictnullsessaccess"=dword:00000000
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