hello, yes that's possible - just visit getfirefox.com, download the firefox installer & put the setup.exe file onto the usb stick and run it on your main computer.

however the original problem won't necessarily be solved by reinstalling the two browsers and malware might still be active on the system. i'd recommend doing a full scan of your system with another security program like the free version of malwarebytes or microsoft security essentials.

also refer to What to do when searches take you to the wrong search website

thanks for that. - and it won't think it's for the version of windows of the machine i'm downloading it on?

the firefox setup file is the same for all windows versions, so that won't be a problem

thanks, i'll try everything suggested.

Do a malware check with some malware scanning programs on the Windows computer.
You need to scan with all programs because each program detects different malware.
Make sure that you update each program to get the latest version of their databases before doing a scan.

• http://www.malwarebytes.org/mbam.php - Malwarebytes' Anti-Malware
• http://www.superantispyware.com/ - SuperAntispyware
• http://www.microsoft.com/security/scanner/en-us/default.aspx - Microsoft Safety Scanner
• http://www.microsoft.com/windows/products/winfamily/defender/default.mspx - Windows Defender: Home Page
• http://www.safer-networking.org/en/index.html - Spybot Search & Destroy

You can also do a check for a rootkit infection with TDSSKiller.

• http://support.kaspersky.com/viruses/solutions?qid=208280684

See also:

• "Spyware on Windows": http://kb.mozillazine.org/Popups_not_blocked