You tap F6 during boot to supply them.
I have a computer with an AMD Processor, a Gigabyte Motherboard, Maxtor 250 Gig Hard Drive and Windows XP Professional Version 2002. Originally I had an issue of the system getting stuck at the welcome screen. I was unable to get past that so I reformated the Hard Drive in another computer and now I get the message that the BOOTMGR is unavaliable, this comes at the point that the computer has just finished posting. I have looked at a few sites on the net with responses to this issue, but all of them thus far have addressed this issue by stating to use the Windows Disk as the Boot. Ihave already tried Booting from the CD/DVD drive and I get the same message. I have 2 other computers here, one with Windows 2000 and the other with Windows Vista Ultimate.