this goes to something i have trouble understanding about Grid authourity.
i actually "joined" SETI 3 different times, only to find that their claim that my computer would be unaffected was not true. all three times my machine became a clumsy rock with wires attached. as i see it there is a greed factor involved, in WCG not wanting to have participants use the ability to set their machine to run at reduced CPU cycle levels, since there are known problems with 100% CPU level. if it were clearly and concisely explained and enabled in the Client software you could get and keep a lot more personal users(my suppose). if a person uploads and runs the WCG client and soon sees a drop off in performance they are going to shut it down and delete it rather than research and work the client to fix any problems. and, like myself, they are likely to feel they had been lied to and become distrusting of WCG and Distributive Computing in general. if a 700MHz machine can do the work, why essentially demand that persons with 3GHz machines run at 100% ? if running a machine 100% can cause problems like overheating why demand 100% ? Greed, as in "i want it done as quickly as possible, adding a month to the crunch time is unacceptable( even if making that demand loses 100,000 machines causeing a 3 month delay?)
CODE THIS INTO THE PREFERENCES/SETTINGS :
- For Windows/XP
Open the Control Panel from within My Computer, and then open "System" within the "Performance and Maintenance" category . Click on the "Advanced" tab in "System Properties" and then click on "Environment Variables". Under "User variables for..." click on "New." Type in "wcgrid_max_cpu" (without the quote marks) as the "Variable Name". In the "Variable Value" field enter the desired CPU throttle percentage as an integer form 25 to 100. Any other values will be considered as 100%. Do not put the "%" character in the "Variable Value" field.

Then click "OK". Click "OK" on the "Environment Variables" window. Click "OK" on the "System Properties" window.

Repeat this setting for each user ID logging into your system, which runs the World Community Grid agent. Alternatively, the "System Variable" instead of "User variable...": can be set, which will enable this setting for all users.

You need to either reboot your system or stop your World Community Grid agent and restart it to have the new value take effect. This can be done by minimizing the agent window, if it is open, and then right-clicking on the agent icon in the system tray at the lower right and choosing "Exit". After this you can use the start menu to restart the World Community Grid agent.

thats my $0.02 US.