131 ( +1 | -1 ) Easy with FritzGo to the database window and load your db of games, then click the menu 'Tools \ Analysis'
You can now choose betwen full analysis or blunder check, the first being more complete and in "natural style" language, the second faster and with numerical evaluations of the position.
In both of them you have to choose maximum time or depth for each move and other option, the most important one is threshold, where you decide, in terms of 1/100th of pawn, when fritz should consider his move better then the one played (that is: it evaluates the text move, then run an analysis of the position and evaluates his best move; if best move value>text movevalue+threshold than a variation his added to the game)
To have significant analysis i think you shoud use at least 10 sec. per move (avoid depth limit, in many cases can slow down the process immensely); which in turn means that you should run the analysis on 10/20 games max, or else be prepared to leave the PC on for many hours
I usually run the analysis on a single OTB tournament database (so between 6-10 games) with 15 sec time limit and a threshold of 30/50 centipawns; i use the blunder check feature which is accurate enough, much faster to process and the results somewhat clear to read than the verbose one....