A. It’s common to have a dual-boot situation in which you have both Vista and XP during testing or transition. The Vista Preinstallation Environment (PE) contains the bootsect.exe tool, which you can use to write Vista or XP master boot codes. An XP master boot code uses the Ntldr-style boot information, whereas a Vista master boot code uses the new Bootmgr format.
To write a Vista master boot code, use the command
bootsect /nt60 \[all sys\]
To write an XP master boot code, use the command
bootsect /nt52 \[all sys\]
Use the All switch to update all possible Windows boot volumes' master boot codes. The Sys switch updates only the current system partition.
If you have a Vista and XP dual-boot situation and want to eliminate Vista, use the PE command
bootsect /nt52 sys
to put the XP master boot code in place so that the Vista boot information can be removed.
If you do replace the master boot code with the Nt60 version and don't have an Ntldr boot menu option to enable access to XP, you can add access to XP by using the following commands:
bcdedit /create \{ntldr\} /d "Windows XP" bcdedit /set \{ntldr\} device partition=c: bcdedit /set \{ntldr\} path \ntldr bcdedit /displayorder \{ntldr\} /addlast
