Shares in Microsoft rose to a seven-month high this week, stemmed from a cash injection by activist investor group ValueAct Capital.

Reports by CNBC in America suggest the Redmond company received a US$2 billion investment as part of the deal, fire shares up 4.75% as a result.

With stock now reaching $31.18, shares in the company are up 16% already this year, putting the software giant on course for its best performance in four years.

Representing 67.2 million Microsoft shares, the investment should trigger good feeling among agitated shareholders, previously disheartened by the company's flagging share prices.

ValueAct essentially invests in companies which it believes to be undervalued, suggesting Microsoft has something noteworthy up it's sleeve.

And fresh from posting strong quarterly results last week, CEO Steve Ballmer should be sleeping a little easier at night after previously being the focal point of criticism from disillusioned investors.

Citing “bold bets” on cloud services as the reason for positive financials, Ballmer showed no signs of defeat when releasing the figures.

“The bold bets we made on cloud services are paying off as people increasingly choose Microsoft services including Office 365, Windows Azure, Xbox LIVE, and Skype,” he said.

Yet Ballmer's inability to react to mobile computing resulted in Microsoft trailing the market behind Apple, Google and co, leading to calls for the 13 year boss to step aside.

That said, Ballmer's continued presence looks likely to continue, despite major shareholders such as Greenligh Capital cutting its stake in the business as a result of Ballmer.

But the embattled CEO, similar to Tim Cook at Apple, is frankly going nowhere - holding around a 4% stake in the company, making him the third-largest holder behind top dog Bill Gates.

Along with the jumping share prices and heavy investment, the company is now producing a line of small Windows-powered devices, set to directly challenge Apple’s iPad Mini and Amazon’s Kindle Kindle Fire.

“[These devices] will have competitive price points, partly enabled by our latest OEM offerings designed specifically for these smaller devices, and will be available in the coming months," Peter Klein, chief financial officer, Windows said earlier this week.

Ballmer previously insisted he plans on staying in the role for at least another five years, and if Microsoft can continue its upward drive, chances are shareholders will be glad to have him on board.

What do you make of Microsoft's new investment? Is the company improving under Ballmer's leadership? Tell us your thoughts below