xp out, new laptop in - use windows or google?

Now that windows xp is no longer supported and upgrading to windows 7 probably doesn't make economic or future sense, I'm looking at 2 different laptops to grow with:

1. Asus Transformer Book T100TA for around $400. or
2. Acer Chromebook C720P for around $30

I really don't do much more than go onto the internet, word processing, and excel. However, I am somewhat paranoid about getting viruses and malware.

Any thoughts?

Thank you, Larry