Situation
The client just build a tent for summer sales. They put a XP to process the credit card. It works for one week. Now, it runs very slow. It take 5 minutes to boot the computer and 29 minutes to logon the network. Sometimes, it doesn't map any network drivers and only map some network drivers.
Troubleshooting
1. if it starts without network connection, it boots normal.
2. If it is in side build, it works fine.
3. We also test using a laptop in the tent. It work OK.
Resolution
since the cable passes from the build to the tent without any cover and it may be over 300 feet, we lower NIC speed to 10 half from 100 (default is auto and it runs 100). After the changes, it runs fine.