Why you think that Microsoft's current share of sales in the personal computer operating systems market is (or is not) large enough for Microsoft to set prices for operating system software as a monopolist? Also, how big of a share do you think a firm needs to have of a market before it can set prices as if it was a monopolist? Lastly, what do you think the makers of other personal computer operating systems could do to gain a larger share of sales in that market or cause Microsoft to lower the price of the personal computer operating systems that it sells?