The storing of wine bottles

[rob]

Three years ago while working for a local grocery chain, I took over the liquor dept., hosted a wine tasting during the grand opening and purchased a few various bottles of our featured Merlot. (I thought about starting a collection.) They were: 1994 Vintner's Reserve Kendall-Jackson Merlot California; 1994 Columbia-Crest Merlot and 1994 Barrel Select Forest Glen California Merlot. I bought 3 to 6 bottles of each bringing them home in an empty wine cardboard box. Please, some of you, don't laugh.
Within a month I was separated and the bottles have been in the same cardboard box sitting upright, and for a year or so I think the box was upside down, in storage ever since.
My question is...are they still good? Have I jeapordized their quality and/or flavor by not storing them on their side all this time and can I keep them in this same box for another year or so?
I would really like to open a couple of the bottles, but am hesitant. Am I right to be cautious or am I simply just a novice?