Uploading Taking 100% CPU vs 2% CPU

[21stHermit]

I'm trying to upload a 290MB file to a server. Using two computers both running XP MCE SP2. The Celeron 360 3.4GHz was using 90-100% CPU and going very slow. The Core Duo laptop was using 2% CPU on one core and uploading 5-times as fast. Both are connected to the same router via 10/100 and using the same ISP.

I suspect the difference is ZoneAlarms Security Suite on the Celeron 360.

Can anyone give me a clue what's happening and what test I might run to solve this?

Thanks
Hermit

 

[montag451]

Also, an onboard NIC may be sucking the cycles.

 

[Nothinman]

ZoneAlarm is the most likely culprit. If the onboard NIC's drivers suck they could cause higher CPU usage but not 100%.