According to this article from the New York Times dated June 1997, the market capitalization of Microsoft at that time was $142.8 billion:
"But Microsoft's closing share price yesterday was still a remarkable 45 times estimated fiscal year 1997 earnings of $2.63 a share, giving the company a market capitalization of $142.8 billion."
And a few months later it went above the current $148 billion.
The big difference is that the earnings are today much higher. Of course the earnings in the next 2/3 years might not stay at 2007/2008 high level, but the future still looks good for Microsoft in my opinion.