Given Microsoft is far and away the towering giant of computer operating systems, it was almost inevitable that it would face a few anti-trust investigations over the years.
Lawyers love Microsoft
With nine out of 10 personal computers worldwide said to run on its software, even it would have been surprised if authorities and smaller competitors did not push for one or two enquires.
Add the fact that Microsoft has faced fairly regular allegations of bullying its smaller rivals to protect its dominant position, and the number of legal cases it has faced have just continued rising.
Cases that the software giant has strenuously contested and have dragged on and on through the courts.
The latest development in Japan, where officials from the country's fair trade watchdog have raided Microsoft's Tokyo offices, is just the most recent of many actions against the US giant.
Officials in Tokyo allege that the software giant has imposed unfair and restrictive conditions in its software deals with Japanese computer firms.
They say Microsoft insists that if companies - such as NEC, Hitachi and Sony - want to pre-install its Windows software on their computers, they must first sign away their right to sue the US giant, even if they find it has ripped off their intellectual property.
Going back in time, the first of the big probes against Microsoft was brought by the US government in 1990, when the Federal Trade Commission launched an investigation into possible collusion between the Seattle giant and IBM in the PC market.
This and other matters continued until Microsoft settled in 1994.
The next big case against the software giant began in 1997 when federal authorities accused Microsoft of anti-trust behaviour by packaging its own web browser - Internet Explorer - with its Windows software to see off the "Navigator" of rival Netscape.
The 'Browser Wars' case rumbled on for five years until it was finally settled by a Federal court in 2002.
At one point the software giant had faced a potential break up into two firms, but it successfully appealed and in a settlement the sanctions against it were much lighter.
Microsoft was ultimately ordered to release some technical data to make it easier for software rivals to write programmes that work in a Windows environment.
That however was far from the end of Microsoft's tussle with the authorities in the US.
While the US government and the majority of 20 individual states which had supported the Federal action, were happy with the result, others, such as Massachusetts were not.
And so the authorities in Boston announced in July 2003 that they were investigating whether Microsoft had violated the anti-trust settlement.
The ongoing Massachusetts probe centres around whether Microsoft had retaliated against a computer maker for promoting the rival operating system Linux.
In addition to challenges from US authorities, Microsoft has also faced legal action from other American firms.
In May 2003, for exampled, it settled an anti-trust lawsuit brought by America Online, who by then owned Netscape. Microsoft agreed to pay $750m (£454m) and in return struck a seven-year licensing agreement with AOL.
In a separate development, one month later, Microsoft won on appeal in a case brought by software firm Sun Microsystems.
Sun had tried to force Microsoft to incorporate Sun's Java software - which enables programmes to run on all types of computers - into Windows.
And if things were not busy enough for Microsoft in the US, in November 2002 the European Commission entered the fray, and also accused Microsoft of anti-competitive behaviour.
Brussels said the firm was illegally incorporating its Media Player into its Windows operating system, to the detriment of rival software by Real Networks, Apple and others.
The European Commission's judgement is due to be given anytime soon, and expected to find against Microsoft.
The Commission could issue a fine of anything between 100m and up to 2.4bn euros ($3bn; £1.6bn).
However, you can bet Bill Gate's billions that the software giant will appeal.