To 泼点冷水吧 and daye

Finally I decided to reinstall the software in my laptop which is infected by the spyware. I followed the daye's instructions till the "Boot Menu" screen appears,in which there are 4 options 1.CD-Rom/DVD Drive 2. +Hard Drive 3. Removable Devices 4. Network Boot. I choosed the first one and hit the "enter" but the computer started to log on from the old system instead from the CD-Rom. Please help me, it is my first time to do this. Thank you very much!