How much taxes on winning the Texas lottery?

I suspect your really asking "....how much taxes will you ultimately pay ...", which is generally different than how much will be taken out, or "withheld" to assure your ultimate payment. It is highly possible you can have nothing withheld (taken out), or a "standard" flat 25% or such may be applied. But the amount you will ultimately pay on the earnings can be substantially different. And it can and normally is different for different people, because of their different situations.

The income will be treated as ordinary income and as such will be taxed at the rate you would be paying at. In essence this can change with deductions you have or can apply. For example, proveable gambling losses may well be deductible against this income. No, there should not be FICA or payroll type taxes due. It (probably) isn't employment type income (unless your a professional gambler). Yes, you must consider the State and if applicable in that State, City and Local taxes too, which varies in all ways and places considerably. Respecfully, the nativete' shown in the question indicates you obviously need specific, hands on professional help to best handle/document and benefit from your (likley new) wealth. However, while it is a fairly modest sum of money, (much less than many annual management bonuses, etc.), I would at least avoid tax return preparation offices in favor of a local CPA or an EA (enrolled agent). Considering it comes along with the big $$...don't expect too much sympathy from others if it all sounds like a complex pain...! Congratulations!!