Athlon 64 3200+ Socket 939 max temp is listed at 65° C (!), so no more COD until the problem is solved. At 72-73 C you're killing your CPU.
Start with turning the computer off. Open the case, and clean it well inside, using a can of compressed air (do NOT use vacuum cleaner!).
While cleaning fans, hold the blades with a pencil.
When done, keep the case off, start computer, and see, if all fans are running.
Go to Windows, and check temps again.
Post the results back.
Temporarily, you may use house fan, pointed toward the open case to keep temps down.
If nothing helps, removing old thermal paste, and applying new one, may help.