What version of Windows is this and is it 32 or 64 bits?
I have a method for getting a different browser without using IE. We can try to get Opera and see if that will work.
In Vista or Windows 7:
Start, All Programs, Accessories, right click on Command Prompt and Run as Administrator, (Continue).
For Win 8 or 10 hit the Windows key + x then choose Command Prompt (Admin) or search for cmd.exe and then when it finds it, right click and Run As Admin. Yes.
Type with an Enter after each line in the code box. Text not in the box is the expected response. I put in two spaces where only one goes so it's easier to see where one space is.
Connected to get2.opera.com.
220 (vsFTPd 2.0.7)
User (get2.opera.com:(none)):
331 Please specify the password.
Password:
230 Login successful.
ftp>
250 Directory successfully changed.
(After one of these steps you may get a windows firewall prompt that it has blocked the program. Tell it to unblock and do it quickly so your session doesn't time out)
ftp>
200 Switching to Binary mode.
ftp>
get Opera_1151_int_Setup.exe
200 PORT command successful. Consider using PASV.
150 Opening BINARY mode data connection for Opera_1151_int_Setup.exe (10307952 b
ytes).
(It will take it some time to download the file. There is no indication that anything is happening so just give it a few minutes.)
226 File send OK.
ftp: 10307952 bytes received in 119.73Seconds 86.09Kbytes/sec.
ftp>
221 Goodbye.
c:\Windows\System32>
Opera_1151_int_Setup.exe
Wait a while and eventually the installer window for Opera will show up.
See if you can download something without the evil error message.
Alternatively:
Got a friend with a PC who could download the FRST.exe and FRST64.exe files? and the Firefox install program
https://download-ins... Setup 42.0.exe
and put them on a CD or a USB drive?