So, I resized my partitions, created a few new ones, got Fedora up and running, and everything worked pretty well. Quick, and no problems - nice!
But when I tried to boot xp again, I got the cannot find hal.dll error. I understood it wasn't a problem, after a while - and that it had to be the windows boot- manager that didn't target the right partition. And that the files weren't actually corrupted. But I think I spent an hour or two reading about grub- configurations before that. And it was a shock of sorts when the boot failed only after the Fedora install (with the partition- config and so on).
So, if anyone else is having the same problem, this is why it turns up:
If you resize a partition and insert a new one before your windows- partition on the disk, the references shift. But only when you format the partition. So when you create a new partition on your disk and do not format it, you can still run the boot as usual. But after the fedora- install there's a new volume in the list, and then the windows bootloader can't find the right one. And since the Fedora faq encourages you to free up a partition in that way on beforehand, and then use the automatic setting for configuring free partitions, I'm sure I'm not the only one getting this problem.
multi(0)disk(0)rdisk(0)partition(3)\WINDOWS="Microsoft Windows XP Professional" /fastdetect /NoExecute=OptIn
..suddenly doesn't work, even though the linux- volume is invisible in windows. Which is also probably why "fixboot" won't shift the reference, and you have to do it manually..
So, since I don't know anything about linux, and it didn't work to mount hd0,0 or any reference to my boot- partition in a root- shell, I eventually managed to extract an edit.com from the windows disk to the boot- partition through the recovery console. And then rebooted just to the command prompt, and then managed to change the "3" to a "4".
Thankfully it worked.
But - I have questions:
* I actually created two partitions, and Fedora formatted and used both. So shouldn't the windows- partition now be nr. 5? Anyone have any suggestions why only one of the partitions count in the partition table? (Is it just the windows boot- loader that doesn't see one type of the linux- partitions?)
* And how can I access the fat16 boot- partition (and the boot.ini) from Fedora (I wish I knew that a while back