laptop for student

I need to buy a laptop for my daughter. Criteria: max 4 lbs, prefer Win 7, max 14 inch screen, ideal is 13.3 inch screen, prefer expandable ram or can replace ram if needed. What do you think of the following:

Lenovo ideapad S300 (Silver Grey 5934-6780) (Pink 5934-5279) Exceptionally Sleek, Remarkably Affordable. | VillMan Computers
pentium 997 1.6ghz
2gb ram
500gb hdd
13.3 screen
DOS
1 usb 3.0 and 2 usb 2.0
3.96 lbs
Peso 17,496.00

Asus X401u-WX088H (White), AMD E2-1800 CPU & Windows 8, Slim Book PC | VillMan Computers
amd e2-1800 1.7ghz
dont know ram jus says max of 4gb
500 gb hdd 5400 rpm
14 screen
Win 8 lic
1 usb 3.0 and 1 usb 2.0
3.86 lbs
peso 17,988

http://villman.com/Product-Detail/MSI_S30
Pentium 987 1.5ghz
8gb ram
13.3 led screen
500 gb hdd
1 usb 3.0 and 1 usb 2.0
3.09 lbs
DOS
Peso 20,995

Pls feel free to suggest other models as long as it fits the above requirements. Brand does not matter. Budget is 20,000.