every now and then a blue screen window come up,"the problem seems to be
caused by the following file:mrxsmb.sys.The driver unloaded without
cancelling pending operations.
Can anybody help me with this please.I am running Windows XP profesional,SP3

Does the PC participate in a Home network ? The module name
you reference has to do with assigning a Master Browser to one
of the participating network PCs.
Normally the Master Browser assignment is done automatically
in the background.

I would start diagnosing by examining the System Event log.
Click Start, Run ( type ) EventVwr.Msc [Enter]
Scan the log for red icons that denote errors. Double-Clicking
each will bring up a details box on the error.

"roberto" <(E-Mail Removed)> wrote in message
news:E1B893B2-0F2A-4272-949D-(E-Mail Removed)...
> every now and then a blue screen window come up,"the problem seems to be
> caused by the following file:mrxsmb.sys.The driver unloaded without
> cancelling pending operations.
> Can anybody help me with this please.I am running Windows XP
> profesional,SP3