ive just never had this issue before before i started using XP-64, but then i also have a brand new motherboard, a gigbyte ep35-ds4 so im not sure which the problem is with
the C drive is clean, all thats installed are XP and Vegas, its a 500gb drive so its got plenty of space, what happens is the CPU useage drops to 0% then jumps back to 100% renders for another 5-7 seconds then repeats, also this dosent happen when i render in MPEG1 only mpeg2 and AVI (the two important ones ofcourse) when i get home ill post a screen shot of my CPU useage graph
i really want to keep XP-64 on it becuase it has 8gb ram, i would be open to linux but Vegas cant run on linux and an emulator would kill performance