I need freeware advice.?

At work I'm in charge of keeping the company's MSDS's organized. I was told to upload what we have (over 500 documents) on the computers so that they can be accessed from any computer in the building. This can be either online or in a program, but I was hoping to get them in a program because the Internet goes out sometimes.

Basically I need very simple, user friendly freeware that other people can use to access these documents. (Keep in mind most of the people I work with are over 40 and not technilogically advanced- this is for them). Ideally, I want something of a search engine for these documents. A program you open and can search for what you need.

I know this is a bit much and kinda picky, but any help would be greatly appreciated. Thank you.