And if it fails, use the restore media acer lets you make.
My laptop had a virus it was given to me by my mom her old computer. It is a Acer Aspire 5742, well what I was was swipe the system. Put it back to factory setting. I started it and the system restore went fine then when it went to 99% on the "system update" and I stayed like that for 6 hours and finally it shut off, so I thought it was done. Now it wont start it gets to the "windows starting" and just stays there nothing happens any ideas? Thanks