I can't really give much advise, since I haven't used Windows machines outside work in a while. Asuming that iinstalling Direct show filters and players with extra plugins is just too much trouble probably not going to work my from what I have heard the following might be good advice:

1. Just listen to them.
a. VLC is what I have been using in the past. It's simple and does not try to take over you computer, you just give it some flac files and it plays it. It also plays DVD files and just about any other type of audio or video file.
b. Winamp seems to be the popular choice, can't say I like it, it just looks to me like a teenage boys idea of a cool design (apologies to any teenagers with good taste).
c, Convert it to something iTunes friendly and listen to it in itunes
2. Burn to CD
a. Spend money and buy Roxio Easy Media Creator.
b. Convert the files and use iTunes or any other CD burning program.
3. Listen on iTunes, iPod and AppleTV. Basically you need to convert the files to a format that iTunes understands. This means either Apple Lossless, aac or mp3.
a. "dBpoweramp Music converter" seems to be the best one I have found. In can conver straight from flac files to Apple lossles, m3a and mp3. It also retains the tags during the conversion meaning that iTunes will know the artist, album title and song titles.
b. Download from here http://www.dbpoweramp.com/dmc.htm and install.
c. After that you need to install some exta "codecs" to be abl;e to read flac files and write the output files. Download and install the m4a & mp4 & Apple Lossless and FLAC codedecs.
d. Now start the converter (Start->Program Files->dbPower...->converter
e. The conversion is relativly selfexplanatory: Select the output format, drop the files in and press the convert button.
f. Now your files are ready to be imported into iTunes or burned to a CD.