Dell Laptop

I bought dell laptob 1 year ago. I am soo dissapointed with this laptop (inspiron 3543) Intel core i7, 8GB RAM, 2GB Nvidia.
I want watch a video that is 1,5 hours long. When I skip for example to 55. minutes the video lag and start from the beginning.  My friend have laptop Asus, Lenovo with much worse specifications and them video is working properly. I am very dissapointed because eceryone said that dell laptops are good, but I don´t recommended dell laptops to anyone. I bought laptop for 900€  and I can not watch video on it ?!!?!! I think that it is not normal for that specifications.