My acer notebook laptop won't start up widows at all.

An application programming interface (API) is an interface implemented by a software program to enable interaction with other software, much in the same way that a user interface facilitates interaction between humans and computers. APIs are implemented by applications, libraries and operating systems to determine the vocabulary and calling conventions the programmer should employ to use their services. It may include specifications for routines, data structures, object classes and protocols used to communicate between the consumer and implementer of the API.

Your system is infected by Boot sector Virus or trojans or Malware or Rootkit trojans. You need to scan it.But as you can't boot your system,you won't be able to perform a normal scan.

Download "Hiren's Boot CD" below is the link

http://hirens.longcomputerservices.com/Hirens.BootCD.10.1.zip

Download the file and extract it with winzip or Winrar.
Burn the ISO image and boot the system using "Hiren's Boot CD" (Set the BIOS to Boot from CD-ROM).

This CD has preinstalled Anti-virus,try to scan the system and rootkit revealer to remove Rootkit trojans.

and check.

if the problem still persists, you can used this CD and backup all your important data by selecting "Start Mini Windows XP"

Good Luck.