can someone please tell me how to reformat without any disks i dont even have a copy of my windows or the serial number what should i do please help

Well, bearing in mind that you've posted in a Linux forum rather than a Windows forum, the question really is; what do you want to do after you've reformatted you hard drive??

Do you want to put Windows back on there or are you thinking of switching to Linux?

If you're thinking of switching to Linux, the best bet would just be to try a few different Linux distributions beforehand. Ubuntu, Mint and Fedora would probably be best for a Linux newbie.

All you do is go to the distro's website and download the .iso image for their LiveCD, burn the image to a CD and reboot your PC with the CD in the CD/DVD drive.

Try a few different LiveCDS. Once you've found a distro you like, reboot the computer with your chosen LiveCD in the CD/DVD drive and select the option to install it to the hard drive.

Many Linux distros nowadays have a guided installer, which makes things just as easy as installing windows! The Linux installer can automatically partition and reformat the hard-drive before installing the Linux OS, but there is also the option to set the partitions up manually. Like I said, if you're a newb, you can just leave it to the installer to sort all of that out for you!

If on the other hand you want to reinstall Windows after reformatting (in which case, you posted in the wrong forum!), you could try contacting whoever built/sold you your PC and find out if they could sort out some kind of recovery CD for you. Bit of a longshot! Otherwise your best bet would be to buy a cheap OEM version of Windows from somewhere on the web (ebay's a good bet!). The OEM versions of Windows are cheaper than the retail versions, but they can only be installed on one machine. Whereas the retail version you can install on as many machines as you like (I think!).
Once you've got your new Windows CD/DVD, slap it in the drive and reboot and bob's yer uncle. The Windows installer should be able to sort out reformatting and repartitioning the drive for you before re-installing Windows.

However if you wanted to be extra sure that the drive was clean, you could download and use something like the 'Ultimate Boot CD' or the 'gparted' Live CD to reformat your drive before reinstalling Windows. Both of those CD's have various tools for formatting/partitioning. To get the UBCD or gparted, it's exactly the same as downloading a Linux liveCD. Go to their website, download the .iso, burn it to a CD and reboot with the CD in the CD/DVD drive!

Cheers for now,