Downgrade after installing Windows 10 can be hazardous

Q: I installed the Windows 10 upgrade on my laptop. But I didn't like Windows 10, so two weeks later I reversed the upgrade and went back to Windows 7. Then I started receiving messages from Microsoft that my copy of Windows 7 was counterfeit. I tried to reload Windows 10, but my Windows 7 "product key" was rejected and I couldn't perform the upgrade.

Is there a fix?

Harold Kortright, Winter Haven, Fla.

A: Your brief upgrade to Windows 10 has created some electronic confusion that makes Windows 7 appear counterfeit. That's why you're getting warnings from Microsoft.

What's the upgrade got to do with it? Normally, you have 30 days to switch from Windows 10 back to Windows 7. After 30 days, the Windows 7 product key (a kind of password that verifies you have a legal copy of Windows) stops working and your old Windows 7 files are deleted.

But you used Windows 10 for only two weeks, so if your Windows 7 product key has quit working, then something's wrong. Here are some potential solutions you can try.

• Complain to a Microsoft representative. You can do that by setting up a free account with the Microsoft Answer Desk (see tinyurl.com/nhor9v6). After signing up, you can request to talk to a Microsoft worker via online chat or telephone. The representative will tell you whether your problem can be fixed for free or if you'll have to pay $99 an hour for help.

• Try reactivating Windows 7. Go to Start, right click on "computer" and select properties. On the resulting menu, click "Activate Windows now." On the list, first try "Retype your product key." (To find the key, see tinyurl.com/nch3av6.) If that doesn't work, click "Use the automated phone system to activate." (Choose the nearest location and you'll be given a phone number.) As a third choice, click "Buy a new product key online."

• Download a new free copy of Windows 7 to a DVD disk or a flash drive (see tinyurl.com/q7p2g7e). Then, after backing up all your PC's data to an external disk drive or flash drive, install the new copy of Windows 7. Doing so will wipe out everything on your hard drive. (This is the option offered to those who waited more than 30 days to reverse the upgrade.)

Q: My Dell Inspiron 15R N5110 laptop won't stay in energy-conserving sleep or hibernation modes. It wakes up at random times, even if the lid is closed. I disconnected the PC from the Internet, but that didn't make any difference. Is there a solution?

Jim Krueger, Bloomington

A: Among the possible causes of a PC waking up prematurely are a wireless mouse with old software drivers (to download new drivers, see tinyurl.com/ol72d9l) and incorrectly configured PC power settings (the hard drive and the display screen should be set to go to sleep at least a minute before the PC does.) For details on these fixes, see tinyurl.com/2uelqm.

E-mail tech questions to steve.j.alexander@gmail.com or write to Tech Q&A, 650 3rd Av. S., Suite 1300, ­Minneapolis, MN 55488. Include name, city and telephone number.