Reinstall windows  
 
Asipre One , i think is come with windows . 
Normally ,acer notebook come with windows have recover function (Alt + F10). 
The means no have any windows cd , only have recover function . 
 
2nd choice ,is reinstall windows use ori disc ,and download drive from Acer website. 
 
Do partitions  
 
1.windows 7 can direct do it ( right click computer--manage-storage--disk managemant --right click C partition ---shrink volume) 
 
2.windows Xp need use software jor. |