Return Column Name And Count

I'm starting to use SQL 2008 recently, and I'm just having trouble with the following problem:

The following query:

SELECT t_Category.Name as [Category]
FROM t_Assets, t_Category, t_Priority, t_Location, t_User_Assets
WHERE t_Assets.Asset_ID = t_User_Assets.Asset_ID
AND t_Category.Category_ID = t_User_Assets.Category_ID
AND t_Priority.Priority_ID = t_User_Assets.Priority_ID
AND t_Location.Location_ID = t_User_Assets.Location_ID

Returns this result:

Category
BMS
BMS
Water
BMS
BMS
Air

And the following query:

SELECT COUNT(t_Category.Category_ID) AS AssetQty
FROM t_Assets, t_Category, t_Priority, t_Location, t_User_Assets
WHERE t_Assets.Asset_ID = t_User_Assets.Asset_ID
AND t_Category.Category_ID = t_User_Assets.Category_ID
AND t_Priority.Priority_ID = t_User_Assets.Priority_ID
AND t_Location.Location_ID = t_User_Assets.Location_ID
GROUP BY t_Category.Category_ID

Returns this result:

AssetQty
4
1
1

I need to have both of those results returned, as a single result. Such as:

Category AssetQty

BMS 4
WATER 1
AIR 1

However, I'm not able to, due to the fact, that if I add the "t_Category.Category.Name" in the SELECT clause, it gives me the following error:

Column 't_Category.Name' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.

And if I try to use the "Name" as part of the count clause, it won't work, as text are not acceptable data types for aggregations.