The is actually the least of my worries, however it's still important nonetheless.

Do I need to buy a new computer? 

I have a touchscreen toshiba laptop. It's about 5 and a half pounds (2.5 kg) and it has about a 3 to 4 hour battery life. I had it over 2 years. It works pretty well though. I have lots of videos and pictures saved on it so I'm surprised it's still holding up. The fan can get pretty loud at times and it's kind of heavy to be lugging around campus. The battery life is also quite low compared to the newer, smaller computers.

On the contrary, my college has a library full of computers so if something happens to my computer, I can easily use the schools. 

I found two HP computers, one for $580 and one for $650. They are both pretty light weight with a great battery life. My aunt sent me $300 in the mail (which I am grateful for) so I now have the funds to buy me a new computer.

What should I do? And if I do decide to buy one, how much should I spend and what kind of computer should I be looking for? All of this processing and ram stuff is confusing. I don't want to end up wasting my money. I want my laptop to last at least 2 years. 

BTW I will most likely be a Communication or Business major. I'll most likely be writing a lot of papers if that helps any.