Q: I tried to copy a 6.87-gigabyte video file from my Windows 10 PC to a 16-gigabyte flash drive, but the file-copying process wouldn't even start. I then tried using another 16-gigabyte flash drive and a 64-gigabyte flash drive with the same result. My PC has plenty of memory to handle a large file — 32 gigabytes of RAM (computer chip memory) and 154 gigabytes of free hard drive space. What's wrong?

John Knoderer, Manning, S.C.

A: Your flash drives can't accept a file that big. Their FAT32 (File Allocation Table 32) format can't store files larger than 4 gigabytes.

But you can reformat them to either the exFAT (Extended File Allocation Table) or NTFS (New Technology File System) storage formats (see tinyurl.com/y97cfbp8), which can handle larger files. Back up your existing flash drive data first, because formatting erases the drive. Also note some limitations of these file formats:

• To use the exFAT format, you must have a PC operating system of Windows 7 or higher. To use exFAT with a Mac, you must have an operating system of OS 10.6.6 or higher.

• Macs can read a flash drive formatted in NTFS but not write to it.

• When removing an NTFS-formatted flash drive from a PC, you must use the "Safely Remove Hardware" feature or risk losing data. See tinyurl.com/yazv9o9s for directions for Windows 7, 8.1 and 10.

Why do new flash drives still come formatted to the old FAT32 standard instead of exFat or NTFS? To retain compatibility with other devices that use FAT32, such as printers, cameras, smartphones and smart TVs. In addition, the new storage formats wouldn't provide flash drives with the same file security benefits that they give to computers, because flash drives handle data differently than PCs or Macs.

Q: I've been scammed by callers who said my computer was infected with malware, but could be fixed if I paid them hundreds of dollars. Now I wonder whether I could protect the PC by using "airplane mode" whenever it's not on. What exactly does airplane mode do? Or should I get more antivirus software to go with my McAfee program?

Robert Lakey, Metairie, La.

A: Airplane mode isn't the answer to PC security. Diligence and common sense are.

Your PC doesn't need malware protection while it's off. It does need protection when it's on, but Windows "airplane mode" doesn't really provide any. It simply turns off the PC's Wi-Fi, Bluetooth or cellular connections to the internet (wired internet connections aren't affected.)

So what kind of protection does your PC need? Certainly not more antivirus programs; multiple programs will interfere with each other and slow down your computer.

Instead, do this:

• Keep your McAfee antivirus software up to date, and supplement it with the free version of Malwarebytes for Windows (see tinyurl.com/jsdacdk). Run Malwarebytes (which isn't an antivirus program) occasionally to clean up anything McAfee misses (no program is perfect.)

• Be skeptical of anyone who contacts you about a PC problem. Legitimate PC repair services don't contact you; you have to contact them.

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