Hi, a little trouble here... (I imagine you hear that a lot here )
Anyway, I installed Ubuntu on a partition and now I can't access my original boot menu to get back into Windows XP. Through Ubuntu I can see all my original Windows files are still in tact but I gather I've written over the partition containing my boot.ini. Any way I can fix this bearing in mind my PC lacks a floppy disk drive. Thanks.

Should also mention that it uses the GRUB boot menu.

BTW, not sure whether this should be in this forum or the "Other OS", so feel free to move it if need be.

Hello eddbot, and welcome to the forums.
When you installed Ubuntu, it should have given you the option to install grub into the MBR. I have found this is the best way to do it, this way you should have the option to boot to either os. You may have missed that step, or there may have been a problem with the install. Version 5 usually installs flawlessly. Version 6 has some bugs , and installation problems is one of them. Have a look here for some good info on Ubuntu, uninstalling it if neccessary, and fixing the MBR so you can get back into windows
http://www.users.bigpond.net.au/hermanzone/p18.htm
If you have any problems, or need something else, come back and see us. Feel free to ask questions, or you can use the search feature in each forum section. Odds are pretty good that your question may have already been answered.

I've tried the above method (by going to recovery console, typing fixmbr)... now I don't get the GRUB menu and instead get 'NTLDR is missing'. I tried going back into the recovery console and tried 'fixboot' but that didn't help either.

update: ok i've taken the drive into another computer and it looks like one of my original Windows partitions has turned into a Linux Swap partition (or so Partition Magic) is reporting. Looks like I'm in deeper than I originally thought... there's some important data on that partition so now I've got to figure out if it's possible to recover that. Besides that, I've still got my other Windows partitions in tact but I've tried copying NTDETECT.COM and NTLDR to the root directory to no avail. Any other ideas? I suppose I can install Ubuntu all over again to see if it reads the swap drive and I can possibly recover some of those files.

update: thanks to Runtime Software's GetDataBack for NTFS, I was able to recover the important files from the partition that was accidentally converted to a swap partition (?). This isn't the first time this software has helped me, so it's HIGHLY recommended from me. At present time, I'm backing up my important data (a practice that is usually under-utilized and understated) and trying to get back into my Windows partition. Looking at PartitionMagic, it's showing my windows partition as a logical partition... would it have to be primary to boot?

Hello eddbot.
Sorry no one has got back to you on this, ive been shutdown because of lightning storms. Anyway, it sounds like something went awry with the install and the partitioning, if it created the linux swap file in your windows partition. You are correct, the windows partition needs to be primary and active, i dont know why it would be showing up as a logical partition. Unless ubuntu was installed in the windows partition. Linux will boot from a primary or logical partition. Since the install went sour, i suggest uninstalling ubuntu. The uninstall info is in the link i gave you above. Then we can work on fixing windows. When you get ubuntu uninstalled, look at your partitions again with partition magic. Does it give you an option to change the windows partition to primary? Heres a guide for repairing the missing ntldr file.
Simple "ntldr is missing" fix with boot floppy or CD, then fix HD
Try that, and then run the fixmbr again. Let us know how it goes.

What version of ubuntu are you using, so i can get you a guide for that?