Q: I am currently unemployed. I am trying to keep my computer skills up to date. I have a Macintosh computer and I am looking for a free online tutorial for Microsoft Office applications. In particular I need a refresher course in Microsoft Windows, Word and Excel.

David Ringo

A: Instruction comes at all sorts of levels, from the very basic, to learning really intricate details only used by professionals. But a good place to start, when it comes to Microsoft programs, is Microsoft itself. Go to this Web address -- http://tinyurl.com/2f8ldvq . From what I could see after a quick tour through the site, it's an excellent way to get started with your training without spending a bunch of money. If you can afford to pay for a course, community colleges often have adult education classes in computing.

In some cases, state or local agencies may offer free ways for job seekers to get training that will help them land a job. Skills get rusty without use. And some job seekers aren't able to afford to buy Microsoft Office for their home computers. Consider volunteering to do office work, free, for a charity or other non-profit organization. By working in an office environment, you'll have access to the software and quickly brush up your computer skills. And that volunteer work can go on your resume. Some employers get nervous when they see long periods of inactivity on a resume -- so you'll be filling in a blank and that may help you find a paying job.

Q: I must return a laptop computer to my employer, soon to be my ex-employer. I've used it for work but also have some personal information on it. How can I reliably remove that information without eliminating the programs that were installed when I received the computer?

John Harmon.

A: Deleted files can be easily retrieved. In some cases, a person can use a program that securely erases the entire hard disk. But since you need to return the computer with programs intact, you must use a program that can selectively -- and securely -- delete files. One way to do it is with a program like the one you'll find here -- http://tinyurl.com/2vjn4hq . That should be sufficient for most people. But there's one thing to keep in mind. You may have – before starting this mission to securely delete files – deleted files in the past. You can’t see them anymore. Yet they could be recovered. Keep in mind that in a normal deletion, the file still exists on the hard disk. As the computer requires the space occupied by that deleted file, it uses it.  Once that happens the file is truly gone. So if you deleted some files long ago, they’re probably not a worry. The computer has written over that space with new data. But, if you've deleted files fairly recently, you may need to use a file recovery program -- one that searches out deleted files -- to find those recently deleted files, restore them and then securely delete them.  Here’s an example of a file recovery program: http://www.recovermyfiles.com/.

Q: A couple of weeks ago you did a column on free anti-virus software for Windows PCs. I have two Macs running OSX 10.4 and 10.5. Can you recommend a good free anti-virus program for the Mac? I am currently not using one and have had no problems.

Don Mann

A: While there are anti-virus programs for the Mac, most users can safely operate without one. The Mac is fairly bullet-proof when it comes to viruses. That could change over time. But for now, there's really no need for one in my opinion. If you still worry and want to install one anyway – no harm -- try Norton Antivirus 11 for Mac. It's available at most computer stores.