Only format when you've tried every possible solution... especially when many things can go wrong in the process. For somebody who doesn't know what to do you'll be hurting if something goes wrong and you can't get online to find out what to do (if that is your only computer).
Is it registered? If you "bought" it i'm sure they can tell you where to look to wipe out the registry information that's preventing you from running it. I seriously doubt they'd force people to "register" and not helping anybody with installation problems.
Formating is easy... the hassle is getting everything back.
1.
Make a list of all driver information. If you have a driver disc that came with the computer (and never bought any new stuff for it) np... if you have a frankenstein computer (as in custom made) you'll need to write down all the drivers.
Settings, Control Panel, System, Hardware Tab, Device Manager, hit all the +'s and write down your hardware) What I do is take a picture with a digital camera... fast easy and no writers cramp. You can skip the system devices (99% of the time their all automatic). Just write down the basics (video, sound, modem, network cards, and any device that you're not sure about).
Once you have all the drivers written down use the internet to find all these drivers and download them... if you have more than one computer you can do this after formating but it's risky if you can't find the right driver.
2.
Make backups of all stuff you want to keep (to CD or another computer). Your Darkbasic code is number one. The documents directory is number two. Music you've pirated from the internet is number three. Backup everything you'll pull your hair out if you don't have (including saves for games). This process will probably take many, many hours.
3.
Insert the Windows XP or Win98 CD in your drive and boot the computer. If it doesn't boot to the CD first you need to change the setting in BIOS. When your computer boots up there's usually information telling you how to get into BIOS to change the settings. It could be DEL, F1, F11, F12... it just depends on your computer. Once you're in the BIOS screen look for "boot order" and change it to boot off the CD drive first.
4.
Once the XP install is on you'll want to read the instructions but it's basically: Hit enter to install windows XP, then F8 to agree to the terms of service, then delete the current partition with D, next create a new parition with C, press enter to use the new partition, select format with ntfs file system (quick) and press enter. It'll format and start installing Windows XP. After a long time (30 to 45 mins) and after a few reboots... it'll ask for the product key. If you don't have one... you're screwed.
If you have a computer that's a non-frankenstein and you used the XP disc that came with your computer there should be a tag on your computer somewhere that has the product key. Then you get to answer dumb questions like what you want to call your computer, the date, network settings (pick typical).
5.
Once Windows XP is finished with installing then the fun begins... you can start by copying all your backup stuff to the computer or installing the drivers (I do the drivers first... so if it totally messes up and I have to reformat again the time it takes to install all the backup stuff isn't wasted). Once you get all the drivers installed next is activation. If you don't "activate" Windows XP it'll only work for 30 days. If you haven't activated Windows XP too many times you'll go right through without any problems. If you've activated too many times you'll have to call a phone number to activate. You'll be saying numbers/letters for a while to a computer and hearing "du duuuhhh" tones... once that's done you'll be taken to a real person and asked "Is this the only computer you have XP on?" in an Arab voice. Tell him/her that you had to reformat your computer and he/she will give you the number to type in.
6.
Next you want to get online and update Windows XP to the max. If you don't update you'll be reformating in a few days from all the attacks. It'll take many hours on a dialup. Do every update especially the latest DirectX drivers.
As you can see it's a long process and may not be worth doing if you can simply get help from the people who make Milkshake. At any point in this process something horrible can go wrong... so be prepared to regret doing this.
Still want to reformat?
Edit: Ack 6 posts while I wrote all that. Yes, it's a work around but it's a whole lot of trouble and if anything goes wrong he deserves what he gets. I'm sure the makers of Milkshake won't mind "justice" like that.