need on screen keyboard

I'm using my son's phone to respond. I was correcting a typo nd LOST it. My keyboard started typing numbers instead of letters from the right side after some updates were installed. Then a virus scan found 3, one a Trojan horse. I was about to remove threat when . It shut down. Since then, I was only able to log on . Once and someone turned off the laptop. Now, can't get back on because . It says incorrect password using the regular keyboard. Have tried using wIndos+ U.
 
No. I can't get past the blue screen with the log on. And I don't have a boot disk. I got this laptop, Acer Aspire 5315, from my mother in law who is several states away from me. It using Windows 7.
 


Actually, we have one in storage. My somewhat techy son is challenged. He is a 21 yr. Old with Down Syndrome. But he is very smart. He does have an Xbox and know how to use it. Yesterday I saw him using an onscreen keyboard on it. I will see how he does it when he gets home from work. Maybe there's a way to connect to it. Is there a way to get around the password? I've tried though the F2 key as it powers up. But it ignores that. I really appreciate your help.
 
I'm almost 56 & have somewhat mild to moderate case of cerebral palsey since I was born. what I somewhat lost in my legs I gained in my brain for patience, technical stuff & model warship building plus renovating the odd rooms in houses.
 


 
Wow, what a broad range of accomplishments, in spite of being somewhat challenged. I'm 54, and have a mild to moderate Traumatic Brain Injury from a near fatal car wreck 17 years ago. It was said I would not live, then that I would not walk again on the leg that was almost lost. But here I am. I may not run as fast, but I'm still in the race!

By the way, the USB keyboard worked and I was able to de-bug, or rather de-Trojan Horse my laptop. The problem with the keyboard was simply a sticky F key. Thank you so much for taking the time and having the patience to help me through this. God Bless you!