De la Iglesia has been hired to handle press and general communications for the US software giant, working alongside Microsoft's PR agency in Spain, Ketchum Seis.
He reports to Microsoft's communications director in Spain Isaac Hernandez.
De la Iglesia joins just a month after Romero quit to become communications director for Vodafone Spain after eight years at Microsoft (PRWeek, 14 March).
Romero, who also worked as communications director at IBM, took charge of the mobile phone giant's six-strong Madrid-based PR team.
Previously, de la Iglesia was publications director at magazine publishers IDG Communications, and a top executive at computer magazine Computer World prior to that.
At Microsoft, de la Iglesia will oversee the promotion of new products across Spain, including the launch of Microsoft Office 2003, scheduled for later this year.
Microsoft's sales in Spain rose 27 per cent last year, boosted by high demand from big businesses for its software.
An eight-strong Ketchum Seis team has handled PR for Microsoft Business Divisions for over ten years.
The agency handles communications for most Microsoft units, but not for the MSN Network.
The Spanish division is one of 40 subsidiaries under the Microsoft EMEA business, which was founded in 1998 and is headed by regional president Jean-Philippe Courtois.
The software behemoth recently reported a first quarter net income of £1.74bn, up from £1.71bn in the same period last year.
Meanwhile, Microsoft hired Edelman for its Asia Pacific corporate PR business earlier this year, after a review which knocked August.One Communications off the brief (PRWeek, 31 January).