Windows 7 XP Professional - will it an appropriate choice to buy ?

I seek suggestions from the Users and learned experts about my choice, and whether my choices worth paying the hard cash. I am a Finance Consultant, and am attached with some Brokers Houses. I supply them with my suggestions regarding Buy and Sell of shares and selection of Options. I regularly download huge data in the OPEN-HIGH-LOW-CLOSE-VOLUME format. Download the Accounts of the Company. The data are analysed, Tables are prepared, Findings are appended and supporting charts (from the Chart Menu of the Operating system OR Applications) are displayed and the Files are dispatched to the Broker’s House. I had bought Windows Vista in 2007 as the Windows XP Professional was under process of phasing out from the Market. But soon I realized that Vista is a flopped product and I have to find alternative software. I loaded Microsoft Office2003 which is serving my purpose. Now, I have decided I should upgrade from Windows Vista (lying completely idle) to Windows 7 XP Professional. I need advices whether I can carry out my professional work independently with Windows 7 XP Professional or I should continue my present arrangement. Please suggest me.