Thanks much for your response.
But I am not able to resolve the issue , when I open the change form for category hardware , it is showing subcategory as hardware , but when I give the same while testing it is throwing error.
FAILURE: Unable to set field 'u_subcategory' to value 'Hardware'. Value 'Hardware' is not currently a valid choice

I tried with all subcategory choices it is not taking .
Kindly help me to pass this step .
Kind of urgent , so could you pls respond asap