LHC@home

I am on dialup. Have successfully installed LHC on two of my rigs. Have attempted to install on two others. On rig 3 the sixtrack download was interrupted by a power failure. When I restarted, work began to download ahead of the sixtrack unit. I have since deleted BOINC from the machine and hope to reinstall today. On rig 4, I believe I got a corrupt download of sixtrack. Two fortran errors keep appearing and two WU's are complete with errors. The third WU is simply stalled at 0%. I want to delete these two computers from my account and re-establish them with fresh installs. I have tried deleting them without success. My only option is to allow the previous designators to remain in my account and create two new computers. How can I clean up my list of rigs? My OS is XP pro SP2. Your assistance is appreciated.

Thank you for an excellent answer. My compliments to the LHC@home crew for keeping those WU's coming. Added another rig to the project last PM. 12 meg on a dialup is-well, it keeps the relatives from calling! Thanks again.