Q: Even though I don't use Apple's iCloud service, it sends me messages that say my online storage is almost full (3.2 gigabytes left out of 5), and suggests that I buy more storage. At the same time, I keep getting "storage full" messages on my iPhone 6 (11.71 gigabytes used, 0 available), often when I need to take an important picture. I do back up my photos on my computer, but why can't I keep them on my iPhone, too?

Debbie Teegarden, Prairieville, La.

A: You can't keep an unlimited number of photos on your iPhone because it has a limited amount of internal storage, 16 gigabytes. And that is shared by the iOS operating system, your apps and the data you save, such as photos.

When that storage space fills, you get a warning from the iPhone. The warning means you have to delete something in order for your iPhone to store any new data. Usually, the solution is to delete photos, because they use up more storage space than other phone data, such as e-mail.

Why is your phone's memory so full when you have backed up your photos to your computer? Because the backups created only duplicates of the original pictures. The original photos remained on the phone, taking up space in its storage.

The iCloud warning is different. It indicates that the online storage service has been automatically backing up your iPhone's photos and other data. That happened because you were given 5 gigabytes of free iCloud storage space when you got the phone, and the phone's automatic backup setting was turned on.

That free iCloud storage space is now partly filled. As a result, you are getting early warnings about running out of online storage, plus sales pitches to buy more. (Note that if you delete some photos from your phone, they will also be deleted from iCloud, freeing up some of its storage capacity for new pictures.) You can turn off iCloud backups to avoid the warnings and sales pitches (see tinyurl.com/nsjcrsw).

What should you do to avoid storage shortages? Back up photos to your computer more frequently, then delete those same photos from the phone. Computer backups are free, and your computer's hard drive has far more storage capacity than your phone.

There's another alternative that is considerably more expensive: Buy a new phone that has more storage. That would allow you to take more photos before you need to delete them.

Q: I'd like to use the Dropbox cloud storage program, but when I tried to sign up I was told it would not support Windows 7. Can I install Dropbox without changing my version of Windows?

Chris Gallutia, Reynoldsburg, Ohio

A: Dropbox does work with Windows 7. But you will have trouble is if you are trying to run the Dropbox application in what is called "compatibility mode," a Windows setting that allows you to run programs that were intended for other versions of the operating system.

To turn off compatibility mode, right click the Dropbox icon on your screen. In the resulting list, click "properties." On the following screen, click the "compatibility" tab. Uncheck the box beside "run this program in compatibility mode," then click the "apply" button.

E-mail tech questions to steve.j.alexander@gmail.com. Include name, city and telephone number.