Windows 7 Mozzila wil dowload anthing, IR won't download anything ?

My Western Digital Caviar Blue WD 320GB SATA/16MB Hard Drive HDD WD3200AAKX-22ERMA0 crashed.

I have a StarTech bit for bit hard drive duplicator and had copied the entire hard drive for backup.

I have two removable hard drive bays and the StarTech duplicator can act as a USB dock for USB input to the computer.

I will call the first Hardrive Hard Drive A. I will call the backup Hard Drive Hard Drive B

The good news is that Hard Drive B booted up just fine and works. Bad news is that for some reason it refuses to download anything in Internet Explorer browser. It does however download anything with Mozilla Firefox !@

I have rung chkdsk and tried re-setting my IE settings to default. Please remember that Hard Drive B was working just fine before.

Hard Drive A is currently not useable as it will boot to the Windows 7 Login page but neither the Keyboard or Mouse will work !! [ I have tried both wired and radio keyboard and mouse] I have run chkdsk on Hard Drive A [connected as a USB drive] from Hard Drive B. Lots of errors but seems like most issues are resolved.

So one Hard Drive won't let me use the mouse or keyboard and the other won't let me download when using IE browser.

Two questions.

1. If I boot to Hard Drive B with Hard Drive A connected as a USB drive, can I make Hard Drive A reset to a prior point through System Restore?

2. Any ideas on how to fix either of the Hard Drives I am at wits end.

Thanking you in advance.

Gary

Thanks I didn't think the obvious. Malware or also Virus

On Hard Drive B [backup working] no problem.

Remember, I can't log on to Hard Drive A. Maybe I missed it. But how do I run Malwarebytes on Hard Drive A? It is entirely readable and accessible because it is now connected to Hard Drive B as a USB drive.

Is there a command line prompt for running AVG or MalwareBytes on a connected USB drive. I just have never needed to do that before.

Thanks again

Gary

PS I have run chkdsk on both drives and am currently running it again on Hard Drive A It takes a lot of time, so it will be a little while before I can do everything suggested because I want the currently running chkdsk to finish before doing anything further.