If the company was a sole proprietorship, you can sue the owner: he is personally liable for any company obligations, since with a sole propreitorship, there is no distinction between the company and the owner--they are one and the same.If it was an LLC or a corporation, however, the owner is not personally liable except in very limited cases (see below). In this case, if the warranty was with an LLC or corporation and the LLC or corporation is out of business, there is generally nothing you can do: only the company would have to honor the warranty, but it is not around anymore. In some cases, you can "pierce the corporate veil" to hold the LLC's or corporation's owner(s) personally liable, but to do this, you have to be able to show--prove--that the LLC or corporation was a sham, with no real independent existence (no real separation from the owners) and was used for the purpose of defrauding those doing business with the company. This is VERY difficult to do and is only rarely successfully--the liability protection afforded by LLCs and corporations is quite strong. If you want to explore this option, consult with an attorney.