I have jusy done a little browsing, and it looks like certain software, can also causes this error. A frequent culprit is
Norton AntiVirus, which changes registry paramters, but others are:
Acronis TrueImage, version 10 or 2009 or higher,
Seagate DiscWizard (a rebranded version of Acronis TrueImage),
IBM AntiVirus,
Microsoft's Bitdefender, and
Symantec EndPoint Protection (version 11+),
AVG 2011+.
If you have any of these, you can try disabling them, or uninstalling, and see if the problem persists. However, the paramtere which they alter, can be returned to a workable state manually.
Please back up your registry first!
Open regedit and navigate to:
HKEY_LOCAL_MACHINE
\SYSTEM
\CurrentControlSet
\Services
\LanmanServer
\Parameters
IRPStackSize DWORD 0x0000000f (15)
Make sure you are in the "decimal" unit and change the size, if it is below 21, up to 21 or a figure above that. Do not, at this stage, exceed 25.