Q: Can I install Windows XP without a disk? After formatting the hard drive? Or get the installation and burn in into a disk and install it again?
A: you can simply install xp from any storage media, i.e. if you have the installation files on usb, hdd or what ever. ofcourse you must boot using a dos disk and so you cant run setup.exe, instead you need to run "winnt.exe" which you can find in i386 folder, so after booting from dos you go to the folder of xp installtion files\i386\ and run winnt thats all also much easier you can run setup from within windows even from the partition of your system(unless you have viruses) and after entering the serial choose NEW INSTALLATION after booting you have the choice to delete your old system and to install new system without lossing of documents in documents and desktop. just follow the directions it is very easy