Could I use the same license key for Zone Alarm Pro on a different computer?

I just bought my brother a new computer and was wondering if I could use the same license key for his computer and mine? or is that considered illegal and I'll have to buy another package of Zone Alarm for his computer?|||You will have to read the license on the product, some licenses permit you to use the program on several computers, others don't permit it. But if you try it and it works fine, then go ahead and use it, you already bought it, why buy two of the same pairs of shoes when the first one is still good as new?