help with reboot

gooday folks

If anyone can help me it would be appreciated.My daughters laptop has been infected by something nasty.It started as a popup that looked like a microsoft window warning that I had been infected and should update my subscription(we already have Avast).
It has progressed to the point that I can’t get into windows anymore.When I turn the pc on it goes to the menu that allows me to choose safe mode,normal mode etc.If I choose safe mode it immediately displays a list of file names then freezes.If I choose normal mode it cycles through the windows page,acer setup page(my pc is acer) then back to safe mode,normal mode page.How do I get out of this loop so I can reboot the computer and backup my files? Please help?

Read the instructions, download and burn (maybe from another computer), finally use one of this rescue CD’s:

  1. Avira
  2. Kaspersky
  3. BitDefender
  4. F-Secure

On a non-infected system download SDFix then put it on a Flash card then follow these directions:
http://www.bleepingcomputer.com/forums/topic131299.html

Download SUPERAntiSpyware then run it:
http://www.superantispyware.com

Malwarebytes MBAM is also good to have and its resident protection is reasonably priced:
http://www.malwarebytes.org/mbam.php