Sometimes, having just one system is not enough, you need more than that. So how do you do it in the simplest manner?
What are the things that you need to complete the installation?
Well, at least you must have some basic Knowledge of Installing an OS. Having knowledge is not enough, you need the tools as well to make it happened. Hence you need to make sure you have either setup disks for each OS or a custom bootable DVD ;bootable Windows 98 Floppy Disk; 15GB for Windows 98, 20 GB for Windows 2000, 20GB for Windows XP Prof).
Is that all that you need?
Not quite as having two systems mean you need a larger space to accommodate both systems? Make sure you have at least 60GB of your space free and unpartitioned
Do I have to do anything about my documents and existing personal data in my PC? Definitely! Make sure you do a COMPLETE backup of all your personal files or else you might end up missing some important data.
Ok? Now that I have everything covered, how do I begin?
Well, firstly, you must prep your PC. Just like us, your hardrives need to be prep for the installation process.First you must omit all the partitions that you have in the PC. To omit or delete the partitions, you need to change some the BIOS/CMOS settings.
Why do we do this?
This is to ensure that your PC will boot to Floppy first.
Remember the setup disks that you need. Now take the Windows 98 Bootdisk and insert it into your PC and reboot your PC your action will prompt you to Windows 98 Startup Menu screen.
There seems to be some options that I can choose from. What should I do next?
Select the first option to start your PC with CD-ROM support.
What happen after that?
The disk that you inserted earlier will load and eventually return to a A:\ . Once you are back to A:\,type: FDISK. Your action will help load the FDISK utility. The first screen might ask you “Do you wish to enable large disk support”, choose Y for Yes. Also, if your C: was formatted as a NTFS drive vs FAT32, it might also ask you if you want to treat non-FAT drives as unknown or something, again choose Y for Yes.
Where am I now?
Your actions so far should lead you to the FDISK menu.
What should I do now that I am at the FDISK menu?
First thing first, you need Display Partition Information. This is so that you can see what has you setup and what you need to delete.
Ok, I have managed to do the previous steps, what should I do next?
Once we see what we have setup, escape back to the Main FDISK menu and then go to  Delete partition or Logical DOS Drive
Now it will bring up four options:
1. Delete Primary DOS Partition
2. Delete Extended DOS Partition
3. Delete Logical DOS Drive(s) in the Extended DOS Partition
4. Delete Non-DOS Partition
When you delete partitions, here are some basic guidelines:
Here is the order to delete partitions (first to last):
-Non-DOS > Logical DOS Drive(s) > Extended DOS Partition(s) > Primary DOS Partition
-If you have any NTFS drives, if possible try to delete them in Windows before booting to Floppy. So, it makes life easier, especially if the parition is created in an Extended DOS Partition. When trying to delete them from FDISK, it might say “Cannot Delete Extended DOS partition while logcal drives exist” however when you try to delete the logical drive, it will say that none exist. If this is the case, what I do when this happens (I’ll explain how to avoid running into this problem in the creating partitions section) is I will go ahead and quick start installing XP and once the XP setup gets to the disk part, I delete the NTFS partition from there and then start my whole installation from scratch again (delete all partitions and create new ones)
Once you have deleted all of the partitions, go back to the main FDISK menu and to the next step.