QI read your reply in last week's column, in which you suggested transferring some complex Excel spreadsheets from an old computer to a new one using a USB cable. Don't you think that using a free online storage service such as Dropbox would be easier and less expensive? For example, I use Dropbox to back up my Quicken financial files. That also gives me access to the files from any of my computers.


ADropbox might be quicker and less expensive, but it's not necessarily safer.

Dropbox software provides online, or "cloud," storage that allows you access your information from any computer with an Internet connection. While I use it for casual purposes (photos or documents I'd show to anyone), I wouldn't advise anybody to use it to move valuable or personal information from one PC to another.

Why? The information you store online is out of your control and potentially vulnerable.

For example, last week Dropbox disclosed that user names and passwords stolen from other websites had been used to log into Dropbox accounts and access private information. The digital burglars also stole a list of consumer e-mail addresses from the Dropbox account of a company employee, resulting in those consumers receiving a flood of spam.

As a remedy, Dropbox promises to start demanding two types of identification when you log in, "such as your password and a temporary code sent to your phone." It's also creating a Web page listing "all active logins to your account." See tinyurl.com/cky8q86.

Anybody can make a mistake, right? Unfortunately, that wasn't their first. Last summer, Dropbox apologized for accidentally allowing anyone to sign into any Dropbox account with any password. As a result, you should be careful what you store in the cloud.

QIs there any way to block "pop-under ads" on Yahoo?

DAVE HIEPLER, Bloomington

AYes. On some websites, ads are created in small browser windows that are separate from the one you're using to view the Web page. These ads are called "pop-ups" if they appear over the top of the main browser window, and "pop-unders" if they show up underneath the main window.

You can block both "pop-ups" and "pop-unders" with the "pop-up blocker" options contained in the major Web browsers, including Internet Explorer, Firefox, Google Chrome and Apple Safari. (See tinyurl.com/6vurzmu. Note that some browser versions have shifted the location of the pop-up blocker control.)

E-mail tech questions to steve.j. alexander@gmail.com or write to Tech Q&A, 425 Portland Av. S., Minneapolis, MN 55488. Include name, city and telephone number.