ALW14 painfully slow, no added files or programs!

Greetings,

I have an Alienware ALW14. It is brand new although it is discontinued. It is painfully slow. I cannot even open a PDF document in Adobe Reader without it freezing and Adobe Reader "Not Responding." I have little experience with computer mechanics. I simply want to use this machine to browse the internet, read PDFs and use statistical software program R. Please advise me on how to optimize this machine as I would greatly appreciate it.