This is what I got from some web site and it says that this tweak is supposed ro accelerate your HD. Unfortunately I have not got only one OS (I'm on dual boot 98/XP). If anybody could test this or attest whether it really boots performance it would be great..... "ACCELERATE YOUR HD: convert your HD in a "dynamic HD" to make it FASTER ... run "diskmgmt.msc". right click on the disk to convert.Then convert it. CAUTION CAUTION CAUTION CAUTION: MULTI OS PCS DONT USE THIS AS ONLY ONE OS WILL BE USABLE."