how can i re-boot my computer with out a disk

my computer has viruses how can i fix it so it could run like factury made

Scleros

To have it exactly the way it was, contact the computer vendor and inquire about replacement recovery or operating system discs. It would also be possible to purchase a new full retail Windows license and media and rebuild the computer, however value-add software that the computer vendor originally included may be unattainable. An alternative could be downloading a free Linux distribution, such as Ubuntu, and installing it.

My preferred method is imaging the hard drive for backup to an external portable drive, erasing the hard drive (see the Hard Drive FAQ for tools to do so), reinstalling Windows, and then restoring the backed up user data, but you will need either recovery or Windows media to do so.

So, if the computer is otherwise working properly, another cleaning strategy is:

1. Press F8 during boot and boot into Safemode with Networking
   
2. Manually delete malware registry entries in
   • HKLM\Software\Microsoft\Windows\CurrentVersion\Run
   • HKCU\Software\Microsoft\Windows\CurrentVersion\Run
   WARNING: Erroneous manual editing of Windows' registry may result in an inoperable computer.
   
3. Download and run Malwarebytes AntiMalware. Follow with an online virus scan, such as Trend Micro's Housecall, and then a bot scanner, such as Spybot Search and Destroy or Lavasoft's Ad-Aware. Note the malware found.
   
4. Reboot computer normally, login to an administrator account and re-do steps 2-3. It may take multiple scans and reboots to fully eradicate whatever infected the computer. Any other logins that exist should also be logged into and their registry keys checked for malware entries.
   
5. Lookup the malware noted in step 3 on an antivirus vendor's website and determine if there are other registry entries that need to be looked for. Removal tools exist for certain threats. Malware may also register as a browser helper object. The add-on management interface in Internet Explorer (Tools > Internet Options > Programs) may be helpful for viewing and disabling add-ons.

Depending on the extent of the infection, cleaning may take significantly longer than a wipe and rebuild.