hmmm. that one is a very short script that tells BIOS where to find the windows bootloader and the windows system files. It also lists all operating systems on your machine - most folks only have the one - so that at boot you are presented witha list of OS's to chooose from. It's on your HDD. Yours is probably corrupted... Typically one looks like this:-
multi(0)disk(0)rdisk(1)partition(1)\WINDOWS="Microsoft Windows XP Home Edition" /fastdetect
Of course, you could just run Repair from the XP install CD. [Repair, not recovery console..]
NOTE... the partition (1) means the first partition on your HDD. If your windows is loaded into C:, and that is the first or only partition you have, then (1) is correct.
short answer is yes. boot.ini is just a text-editable file in the C: root directory.. to see it you must untick "hide protected operating system files" in folder options > view. This is mine [windows is in C drive] -
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Home Edition" /noexecute=optin /fastdetect
To edit it without the CD you would have to either put your HD in another puter as a slave drive, and just go in and edit it,
or if you have a multipartition setup on that drive then use your OEM discs to load another windows opsys in a spare or otherwise partition in which it would not matter if you lost ALL the data. [AS LONG AS YOUR INSTALL DISCS ALLOW YOU TO INSTALL XP TO ANY PARTITION OTHER THAN C: !!] Then as before you would just edit the bad boot.ini, and reboot, and delete the extra opsys.
There is no other way without a genuine windows XP CD.
one thing, if you have XP you are very likely using NTFS on your HD. For your emergency opsys you could therefore use NT or 2000, cos they are both NTFS compatible... and you just might have those old install discs somewhere, or know someone who...