super prefetch causing slow system

Hello, i have got a problem prefetch is giving me a hard time the first
2 minutes after i started up my system. I dont understand why after 7
months of using ultimate 64 its causing such lag ?? Is it because there
are more and more programs installed or what . I know i can turn it off
but i dont whant to.

My system specs :
gigabyte ga x38 dq6
intel q6600
8 gig g.e.i.l ddr2 800 memory
2x500 samsung spinpoint in raid0
8800gts 320mb

Dutch 64