paulo, it is possible that it is trying to boot from the network because it can not find the OS on the hard drive. This could be caused by a bad MBR or a bad hard drive. Check to see if you can access the BIOS, change it to boot from optical drive and use a bootable OS disk. I use a copy of Puppy Linux or Hirens Boot CD. If you can, check the hard drive and see if it is still accessible. If so, copy all your files that you may need to an external drive. after that reinstall your OS. Make sure that you have the proper OS disk as well as access to the drivers for your computer. If you can not access your drive, you will have to replace it and reinstall your OS. Hope this helps, good luck.
