I am not new to linux, but i havent messed around with it for a long time, i rented a computer from a rent to own place around where i live, and when i got the computer it didnt come with any restoration cds, i want to dual boot it with linux, specifically FC3, but with dual boots in the past i have had trouble, so i need to know a really safe way to do it, any help would be apreciated.....dustin jones

Dustin,

This doesn't seem like a good idea. I'd be certain to have some way to reload Windows; and also , back-up all your data before trying to convert to a dual boot machine. But...

1. Acquire the FD 3 cds.
2. Defragment the hard drive upon which you will install FD 3.
3. I'd get a partitioning application such as Partition Magic and use it to create at least one linux partition and a linux swap partition.
4. Put in the FD 3 cd #1 and boot the machine.
5. Follow the instructions.

On the bright side most popular linux distributions have greatly improved the ease of installation compared to years past.

i have a windows xp cd, so i can always reinstall it, but i also dont know if all of the hardware in the dell dimension 2500 is all compatable.. is there still a site to check all that on?

If you have a spare partition to install linux on, you could either install grub on a floppy (doesn't mess with your mbr) or onto that specific partition and then use the nt bootloader to load grub, there's a guide on how to do that here (it's not complicated at all).
Using either of these ways is pretty safe, as long as you don't erase your windows drive. If you by accident would overwrite the mbr with grub (and windows doesn't start) you could use the commands "fixmbr" and/or "fixboot" from the winxp recovery console (from the xp cd).

but i dont have free partition, is there a way to make the existing partitions smaller? also if i were to just install some other hard drive i have, (i have a few with linux already installed from previous computers and some just blak, really small ones) would i just do the same install grub on the new hd and use the ntloader to find it? im sorry im asking so many questions, but i dont want to screw this computer up and then have to pay for it all at once, i have a 3 month old kid and really cant afford that right now

I've heard partition magic could do such things for you, convert free space into a new partition, but i'm not sure at all (and you'd have to pay for it as it's not free). When googling I also found this.
You could install a new hdd, but i'm not sure you are really allowed to do so with rented computers... well, anyway, that would be the easisest solution, make a fresh fc3 install on the hdd, install grub on it (make sure you press advanced bootloader options or whatever it's called in fedora's installer). Then you'd have to boot into your fedora partition either by changing hdd boot order in the bios (i'm not sure it works allt the time though, grub sometimes hangs if you do) or by using FC's rescue mode / disc.
Check the guide i linked to is pretty thorough on what you have to do etc.

Edit, if you use the same hdd, and fedora doesn't give the option to install grub on /dev/hda2 (or wherever you have installed linux) don't install a boot loader at all. Start FC from the recovery console and run: