Making my RAID mirror visible to my network

I wasted hours trying to work out why my XBOX couldn’t see one of the network shares on my XP PC. I had pretty much given up and put it down to a dodgy driver or the like. Then my old man, who has a PC built just like mine (which I built), told me about a registry setting.

HKEY_LOCAL_MACHINE SYSTEMCurrentControlSetServicesLanmanServerParameters

Value Name: IrpStackSize
Data Type: DWORD
Value: decimal 20