Hi all!
It looks like they have changed the prefetching algorithm in SP1 and good old Bootvis is of no use as yet I wonder when they are gonna issue a new one... The only way to optimize your boot files for now is to boot and wait abt 20 minutes. I've already successfully tried this
Before I installed SP1, I had two entries under
HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionOptimalLayout

They were "Autolayout" and "LayoutFilePath". Now there is only the latter remaining... (Not sure whether the first one was once written by PerfectDisk though... but anyway, when Autolayout was 1, the prefetcher worked every time you defragmented the drive, and BootVis too, but when it was set to 0, only PerfectDisk took care of defragmenting the boot files)
New values in the registry are under: HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsNTCurrentVersionPrefetcher
If the value of "BootFilesOptimized" is 1, then even the built-in defrag doesn't attemt to reorganize them every time you defragment your system drive (Remember that long-lasting "compacting files..." message at the start of defragmentation?) If you set this value to 0, the defragmenter attemts to reorganize the boot files but it still doesn't move them to the first available amount of free space (?)<br><br />
For me, it's a pity though, as my boot files have concentrated at the end of the disk, which is kind of slower (The start and end location could still be seen under HKEY_LOCAL_MACHINESOFTWAREMicrosoftDfrgBootOptimizeFunction
So, be careful now when cleaning your prefetch folder as it won't be repaired with BootVis at once!

i'm noticed no change in boot time after installing sp1, as in no slow down in fact its a little bit faster. i guess its your sysyem setup dude :-?

I didn't say it was slower than it had been! I said that the disk speed at the end of it is slower than it is at the beginning DUDE!

Are you sure that Bootvis doesn't work? After installing SP1 my boot time was up to 34 seconds (slow for my system). After optimising with Bootvis it's now down to 26 seconds.

i just ran bootvis for the first time since installing sp1 and it worked.

You know, guys... I DID clean my Prefetch folder (ALL of it), then I ran BootVis........................
It really works - It concentrates boot files in a certain location. It really does. I can see it with the help of the good old PerfectDisk again. (I don't advertise PD here, moreover, I wouldn't even recommend defragging with PD)
But! Something has really been changed!!! I mean what concerns the defragger. This is for sure! Those who ran built-in defragger often will understand me... "I hope so" © Led Zeppelin, "Stairway to Heaven" at Madison Square Garden, 78
By the way, my system boot time is 14,82 sec........ Is this good? What d'ya think?