Asus computer help please?

I have an asus laptop that will not correctly boot. It will automatically go to startup repairs and nothing there will work. Also, system recovery disks do not work. I will be very grateful if someone can tell me how to correctly fix this. Don't tell me to get a new computer by the way.

ASUS N53XI241SN-SL/64NRDXXS 15.6" Notebook Intel core i5-2410M Windows 7 4G 640G GT550M Graphics WiFi Webcam Laptop

ASUS N53XI241SV-SL/64NRBXXS 15.6" Notebook Intel core i5-2410M Windows 7 4G 640G GT540M Graphics WiFi Webcam Laptop

ASUS K42EI48JZ-SL/82GDYXXB 14" Notebook Core i5 480M 2.66GHz Windows 7 2GB DDR3 500G ATI Radeon HD 6470M Graphics Wifi 0.3 Mega Webcam Laptop