Sorry - I should have pointed out that the "CopyMemory" problem occurs on both 32 and 64 bit Office IF running on 64-bit Windows. I'm familiar with the PtrSafe construct but I've tried adjusting the data types (LongPtr, LongLong, etc) without success. I also emailed Randy who said he'd never tried to make it work on 64-bit OS. Another source said that anything using winsock32.dll on 64 bit OS won't work reliably, but I don't know if that is true. You can get a Name from an IP using WMI but if the remote computer isn't listening on WMI the code waits a long-time before giving up, which is no good if its along list of computers, and they may not all be running Windows!