That is a fake anti-malware and can be picked up on an infected site.

Did you download Firefox from the Mozilla site? or from some other site?

What is the name of the so-called anti-malware program that has scanned your system, told you that you are infected and wants money from you?

If you clicked anywhere on that "scan screen", it could have downloaded malware to your system. That is a very common trick and has been occurring for well over a year. With the name of the fake program, I might be able to lead you directly to instructions to remove that problem.

the company trying to charge me is mirosstore and the app is calling itself XP-repair it like a spayware program and it scan my computer tells there is virus and hardware problems and then sday to fix these problems i must bu there software

i down loaded it directly from your site

Ok, you must have hit an infected site. That company has no software to sell; they will charge your credit card and then probably sell your credit card number online so that other thieves can use it to purchase whatever they want before the card gets cancelled. XP Repair is a nasty one; it hides files, it maybe does search re-direction, and various other nasty things to your system. At the end of the first paragraph in the self-help article below, it says, "When you click on of these alerts, Windows XP Repair will automatically be downloaded and installed onto your computer." That means click anywhere on the warning, including the close "X" in the warning window.

Below is a link to a very reputable site that helps with un-installing pests. You should read the full article carefully. If you perform the self-help steps, will you need to download 2 or more programs that are recommended and do exactly as the article says, in the sequence listed. If you have already done anything to remedy the problem yourself, you may have done more harm; that is mentioned in the article. If that is the case go directly to their forum (see next paragraph) and let them try to help you rid your system of the problem.

If you do not feel comfortable doing this yourself, bleepingcomputer offers FREE expert malware removal assistance through their forum.

• The link for that forum is at the end of the article under "This is a self-help guide. Use at your own risk."
• Be sure to read and follow their instructions for posting in the forum and do exactly as instructed.
• When one of their experts answers your post, follow their instructions to the letter, no more no less.
• Be patient as they respond to posts in the order received.

Here is the article on bleepingcomputers.com site: http://www.bleepingcomputer.com/virus-removal/remove-windows-xp-repair

Good luck in removing this pest. Please post back and let me know how things went for you. And, always practice safe computing, stay away from sites that may not be trustworthy, be careful of what you download and install, be careful of suspicious e-mails that you receive unexpectedly.