Q: I use Gmail, and some of the e-mails I receive contain numerous photos. But on many of the e-mails, some of the photos are fine, while others are blank. Is there any way to fix this?

Michael Pelt, Jacksonville, Fla.

A: My guess is that the blank-photo e-mails you received exceeded Google's data limit for photos, and that the pictures above the limit weren't delivered.

An individual Gmail message can't contain more than 25 million bytes (25 megabytes) worth of images. This is true whether you're sending the photos as e-mail attachments or as in-line photos in the middle of the e-mail message.

Google does provide a workaround, although it doesn't actually e-mail your photos. By using Google Drive, the company's cloud storage service, you and your e-mail friends can share photos totaling up to 10 billion bytes (10 gigabytes) of data. To do this, you upload the photos you want to share to Google Drive, then e-mail a link to the photos' location. For directions, see tinyurl.com/n5pkk9s.

Q: I have a desktop PC, a Samsung Galaxy S3 smartphone and a Samsung Galaxy Tab 3 tablet computer. I use my Gmail account on all three devices, so my e-mail is synchronized and up-to-date on all of them. How can I get my contacts and calendar to work together on all three devices?

Tom Scanlon, Golden Valley

A: Since you're already using Gmail on your various devices, you have a Google account that can synchronize, or sync, your contacts and calendar.

For a video of how to sync your Google contacts and calendar with your Samsung Galaxy S3 phone, see tinyurl.com/n2uo4on.

For step-by-step directions (with screen shots) on how to sync your contacts and calendar with your Samsung Galaxy Tab 3 tablet computer, see tinyurl.com/l8uba2g.

Q: I've switched from Windows XP to Windows 7 Professional, and I'm having trouble backing up my data.

XP allowed me to select what to back up, where to put the backed-up data and what to name the backup folder (such as C3-30 for a backup of the C drive on March 30.)

But Windows 7 doesn't let me select where to put the backup, or what to name the backup folder. How can I solve this problem?

Jack Salisbury, Chepachet, R.I.

A: Windows 7 will allow you to select which drive to store the backup on, but it does force you to put the backup data in a generic folder called "Backup." However, there's nothing to prevent you from renaming the Backup folder later. Just right-click the Backup folder and choose "rename" from the menu.

For details, see "How To Use Backup and Restore in Windows 7" at tinyurl.com/yjew6gk.

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