Internet won't load and programs won't start?

Okay, so I'm at my wit's end since I'm not a computer person. My laptop (Dell Studio, PP39L) has been acting strangely for the past few weeks. The internet will connect, I have full internet access, but the internet will just stop working. Chrome won't freeze, but it won't load. I'll click on a new tab and type in any website, but it won't load. In addition to the problems I have connecting to the internet, once my computer begins to have these problems, I can't open anything. I'll try to open my documents, Microsoft Word, etc. but nothing will open/start up. The icon on the task bar will appear for a few moments before disappearing and nothing happens. I can't access my task manager, and more often than not, if I click on my task bar, it'll freeze. It doesn't have a specific pattern; it will work fine, and then out of nowhere, everything just...stops working properly. I'll restart my computer manually and everything will be fine, but eventually, it will freeze again.

Whether it's relevant or not, my computer has given me the blue screen of death a few times.

...help? Please? I've done multiple virus scans and nothing has turned up.