With Office Web Apps in SkyDrive, you have access to your Word, Excel, PowerPoint, and OneNote documents whenever you have access to the web. You can make edits on the fly in a web browser, and you can easily open them in Office desktop programs to make extensive changes.
First, sign in to skydrive.com. Go to the folder where your document is stored, right-click the document, and then click the command for opening the document in its web app (for example, Open PowerPoint Web App for a PowerPoint presentation).
Your document opens in Office Web Apps, where you can view and edit it in the browser. To edit, click Edit in Browser at the top of the web app.
If you want to make changes that require the full set of capabilities found in the Office desktop programs, click the command to open the document in the desktop program (Open in Word, Open in Excel, Open in PowerPoint, or Open in OneNote).