Runaway +++++'s

[badlands17]

A couple of months ago I bought a new HP desktop. I thought everything would be good with my new one as my 4 year old HP desktop was beginning to develop a few glitches.The major one was that after I had been logged in for awhile, I would suddenly get +++++ plus signs which would fill in any empty boxes i.e. search boxes, log ins, password boxes, etc. One they started, you could not stop the +'s. They would keep coming and coming.I would have to shut down and start up again. Unfortunately the problem has continued with the new computer. Every time I start up, the +++++ will appear and I will have to do a restart. After the restart, everything is fine for awhile and then the ++++ signs show up again. There is no time limit or specific programs that cause the ++++ issue to start up. I have tried to find answers online and also have shown pictures I took to a couple of local computer repair shops. Every one is baffled. I thought it was my old computer taking its last few breaths, but since it is showing up on the new computer, it must be something that has transferred over. I know it has nothing to do with my keyboard or mouse as I have tried 3 different ones: HP, Logitech, and Azio. Any suggestions? Anyone?

[Prométhée]

Hi

""but since it is showing up on the new computer, it must be something that has transferred over.  ""

what exactly did you do after switching on the computer ..?
If you have transferred some things from the old computer, this is the problem it seems obvious.
now to know what and how?
The best thing to do, would be to reinstall the computer completely with the Hp recovery system.
It should return to normal operation, if that's it
Then be careful what you transfer, don't do it all at once