During what time period did the hykos conquer egypt?

Dates vary slightly depending on which source yo read but
 
-Circa 1630 - 1521 BC 

-Circa 1600 - 1540 BC 

The Second Intermediate Period (c. 1600 - c. 1540 BC) 
A series of weak rulers causes a new breakdown in centralized authority during the Second Intermediate Period (dynasties 14th, 15th, 16th and 17th.) The Hyksos from Asia took advantage of Egypt's internal conflicts. The Hyksos army used horses, chariots, body armor and new types of bronze weapons - none of which the Egyptians had. The Hyksos advanced military weaponry and the internal turmoil in Egypt allowed the Hyksos to conquer and rule Egypt for 160 years. 

The Early New Kingdom (c. 1540 - 1300 BC) 
The Egyptians learn to use the same weapons and warfare as their captors and eventually drive the Hyksos from the kingdom. 

Government taxes ? i guess