Looks like there's a particularly annoying bug hiding somewhere in the bowels of Microsoft Windows XP operating system, particularly manifesting itself when two XP boxes (or, apparently XP- to Server 2003, or even XP-to-Win2K) are attempting to copy large (typically in excess of 700K) files over a network. Sometimes, it can involve copying to USB flash drives, or drives in external enclosures. Whatever the source, the problem is apparently unique to XP, and is causing more than a few people frustrations.
Apparently, after a time, the copy hangs, and eventually the source system will report "Cannot copy
Unable to offer any conclusive answers here, I thought I'd post a few possible solutions others have tried with varying degrees of success. Warning, there is no silver bullet - at least so far.
This is a very cursory listing of possible solutions. A great source of more detailed info is available here
1. Be sure all NIC's and switches are set to *either* 100Mb/Full duplex, or 10MB/Full Duplex, but NOT AutoNegotiate. Autonegotiate is the bane of many an otherwise unexplained network problem.
2. Check to ensure any 80-pin cables are absolutely sound; replace if possible.
3. DON'T start renaming files or shortening diretories; the "Path is too deep" is almost never tied to this actual problem.
4. Check/replace network cables.
5. Unregister the AVI preview DLL (shmedia.dll).
6. In the registry, set the TcpAckFrequency to 1, per MSKB article 328890
For the best discussion on this error, check the link listed above. Anyone with other possible solutions are invited to reply here and share the wealth!