Ok, I have a laptop with a card in it, but it doesn't work with Linux so I'm gonna put Windows 2000 on it. I know I can't write to NTFS partitions with the current kernel, but I have one question: If I format the drive as NTFS, can I still access my files over a network?

Unless I really don't get what you are trying to say...

If you format your drive, you WILL loose all of the files on that drive, and there will be no way to retrive them after installing NT.

Best solution: Buy a Network Card that IS supported by Linux.

I don't think you understood the question. Basically it's this: When i am using linux (ext3), can I write to an NTFS drive over a network (the drive on the laptop) and vice versa?

Yes. The files are only stored on the hard drive in a particular format. They are not transfered over the network in that format.
Think of the internet. There are linux servers out there running ext3 file systems out there, but we can still access files and web pages stored on their hard drives on a Windows machine. and vice versa.

The files are transmitted over the network in a format, either binary, or ascii i believe... which is totally independent to the hard drive formats.

you would have to write to the drive from the machine with tne NTFS file system on it. If you have a kernel that will allow you to
write to mounted filesystem (NFS) that is NTFS (the 2.5 kernel
supports this) then you could attempt it but its dangerous.

So here are you options:

1.use sftp to transfer files from Linux to the inferior OS (or winSCP)
2.use samba to create a shared directory to share with the inferior OS
3.put all of you files that u want to access on a web server
so that the inferior OS can download them (i do this for my mom sometimes, it's easier for her to download than to have to learn
to use an FTP client)
4. burn stuff to CD and walk it over(no fun in that AT ALL)

Stuff I wouldnt do:
1. FTP server (winSCP is a much better option, requires no work
on the Linux side if sshd is running)
2. anything else that requires sending a password in plain text.
3. Risk messing up the NTFS drive by writing to it directly from Linux

number 3 may work but if you ever compile a 2.5 kernel it says
(DANGEROUS) next to the option to allow writing to NTFS mounts.