Strange back-skip problem

[02bin3]

I'm not quite sure as to which forum this problem belongs with, but I guess I'll start here.  I have 3 computers that all have the same problem.  The 2 years old Lenovo laptop constantly skips backwards to a line above or even 2-3 lines above when I am typing.  The year old Asus does it occasionally and the brand new Acer that I just bought for my son for Christmas was doing it when I was setting up various software programs and registering them.  I would type in a user name, tab to the password line, start typing the password and the next thing I know the curser has popped back up to the previous line and is adding on to the user name. Prior to these three computers, I'd never had a computer do that and I've had a few since 1994. Has anyone else had this problem and if so, is there a "fix"?  Thank you

[truenorth]

3 different computers--same printer? How are they connected to the printer(s)? truenorth

[Allan]

I don't think the printer is involved.

Is this the only problem on the systems? My first thought was malware, but the fact that it happens on 3 systems is very odd.

[02bin3]

Only one computer (Asus desktop) is hooked up to the printer.  The Lenovo laptop does the back-skip no matter where I use it.  It will go along for a few sentences and then it pops back up a few lines.  I don't know if the Acer does it other than when I am filling out forms for on line registrations as I haven't used the word processing program yet.  I've been typing for 50 years and never had this problem.  At first I thought it was something peculiar to the Lenovo, then a few times it has happened with the Asus, mostly if I haven't given it a chance to load up to sign in on Yahoo, but, when it started happening with this brand new one, I began to get a little concerned.  Thanks for your input.

[Allan]

Well, you might want to scan for malware as a start. Do a full scan on one of the systems with BOTH your anti virus utility AND with MalwareBytes

[02bin3]

I run both Norton Antivirus and Malwarebytes regularly and make sure they are updated constantly.  Those programs are on all three computers.  I also run Defraggler about once a month, & Ccleaner.     Perplexing problem!  Thank you for your suggestion.