Back Up Outlooks Humongous PST File


Q. I’ll concede that Outlook is a cool tool in Microsoft Office for handling tons of e-mails, contact addresses, calendaring and task reminders. But oh that .pst file! I can’t understand why Microsoft designed Outlook in such a way that it stores all that diverse information in one giant, vulnerable file without a way to separate, say, the calendar information from the e-mail data or the addresses from the tasks. And to make matters worse, that file grows so large over time that it becomes difficult to back up and to store in a safe place. I know the .pst file is too important not to back up regularly, but it’s so hard to do. Any suggestions?

A. Your concerns are valid, and that message has finally gotten through to Microsoft—or at least part of the message has. After all these years, the company has made available a little program that automatically backs up the .pst file each time you close Outlook.

For those of you who are shaking your heads and asking, What’s a .pst file, and why should I care? lend an ear because this is important. Just as the names of all Word files end with the .doc extension (for example, stanley.doc .) and Excel files end with .xls ( stanley.xls ), so Outlook’s data files end with .pst . And since it is tucked inside a folder most users rarely, if ever, access, this ever-growing .pst file never gets a second thought—until the computer crashes or somehow the Outlook data get scrambled. Then the users wish they had heard of the .pst file and had taken the time to back it up. That’s why it’s important to know about the .pst file.

Before I tell you about this new Microsoft program and how to get it (it’s free), I want to share two related tips: how to keep the .pst file at a reasonable size and where you safely and conveniently can store the backup file.

First, keep the file lean: If you decide you must keep all your old e-mails and their attachments for years and years, that’s your judgment call, but recognize that such a strategy means the file will grow to an enormous size. Not only is a very large file hard to back up, but Outlook, burdened by its sheer size, will eventually slow to a crawl. However, you can keep the file to a manageable size and still store your old e-mails by archiving the older parts of the file. To do that open Tools in Outlook and click on Options , the Other tab and AutoArchive .

You even can program Outlook to automatically archive your older data on a schedule of your choice—every few days or even every few months. That will make a significant difference in the size of the .pst file. However, don’t fail to back up the archive file, too.

Second, use remote storage drives : Storing backups on your computer’s hard drive is like putting your emergency savings in a wallet you carry every day. If you lose your wallet, you’ve not only lost your spending money, but your emergency money, too.

So I recommend storing your backup on a different, remote drive. For about $100 you can buy a separate hard drive no bigger than a paperback book that holds 80 gigabytes or more. And what makes such remote drives even more attractive is that they are portable. They attach to a computer via ultrafast USB (universal serial bus). Just plug in the drive, and the plug-and-play feature on your computer will recognize it immediately and assign it a drive letter, which puts you in business instantly with loads of storage space. That’s a small investment—in time and money—for such peace of mind.

Now, to download that neat little Outlook backup program I was telling you about, go to , click on Downloads and do a keyword search for Outlook 2003 Add-in Personal Folders Backup . The actual file name is bfbackup.exe and it takes just a few minutes to download.

STANLEY ZAROWIN, a former JofA senior editor, is now a contributing editor to the magazine. His e-mail address is .

Do you have technology questions for this column? Or, after reading an answer, do you have a better solution? Send them to contributing editor Stanley Zarowin via e-mail at or regular mail at the Journal of Accountancy, 201 Plaza Three, Harborside Financial Center, Jersey City, NJ 07311-3881.

Because of the volume of mail, we regret we cannot individually answer submitted questions. However, if a reader’s question has broad interest, we will answer it in a forthcoming Technology Q&A column.

On occasion you may find you cannot implement a function I describe in this column. More often than not it’s because not all functions work in every operating system or application. I try to test everything in the 2000 and XP editions of Windows and Office. It’s virtually impossible to test them in all editions and it’s equally difficult to find out which editions are incompatible with a function. I apologize for the inconvenience.



Keeping you informed and prepared amid the coronavirus outbreak

We’re gathering the latest news stories along with relevant columns, tips, podcasts, and videos on this page, along with curated items from our archives to help with uncertainty and disruption.


Excel walk-through: Sparklines

Want to liven up your spreadsheets with some color and graphical elements? Kelly L. Williams, CPA, Ph.D., shows how to use Excel sparklines, which illustrate data trends and patterns via small charts that fit in a single Excel cell.