just changed power supply, weird harddrive problem (sata)

[idrisguitar]

i just switched my power supply for a better one, and plugged everything in as i know i should.

however for some reason when i boot up on startup (windows loads perfectly as do my ati graphics drivers and much more,) MANY programs are missing, and i see this is because the harddrives are totally messed up, in otherwords the computer thinks my 250gig maxtor sata is only 91 gig, and my other 320 gb hitachi which by the way is totally emtpy is another 90 gig hdd and is apparently full!!!)

so basically the computer is totally screwing up the recognnition of the hard drives.

is there a way to fix this, what do i need to do,, why did this happen in the first place,

by the way the power supply is an antec true power trio 550w and the mobo is a 20 pin, whereas the power supply is a 24 pin, however it says in the manual to detach the extra 4 pins which i did, so i doubt thats the problem

i REALLY, REALLY hope you guys can help.