Microsoft is in talks with Silver Lake Partners and Dell's CEO Michael Dell to invest $1 billion to $3 billion in a leveraged buyout of the PC maker, sources close to the matter told CNBC Tuesday.

While an investment from Microsoft is unexpected, it makes sense considering that Microsoft depends on personal computer makers like Dell to help sell its software products.

Meanwhile, talks between Silver Lake Partners, one of the main sponsors in talks with Dell to help bring it private, and the special committee for Dell's shareholder are continuing and a deal is expected to be reached by the end of the week.