when you boot, hit Esc to get to the menu list. Chose the line which is causing the problem and hit 'e'.
You will get 4 (or so) more lines. Find one with something like that .....hdd(0,0).... or ... hdd(1,0)... in there, select it and press 'e' again. if you have 2 hard drives (one for linux another for windows) try to change hdd(0,0) to hdd(1,0) or hdd(1,0) to hdd(0,0) If they (OS) are on different partitions play around with the second parameter. Ex. hdd(0,0) to hdd(0,1) enter, and hit 'b' (boot) If it helped, you can make changes permanent by editing /boot/grub/menu.lst - just find the string with hdd(x,x) and make changes. Hope it helped
