I've had the same issue last year and did some days of Googling to find out what I needed. Even though I didn't need those tools for the same purposes, I'm pretty much sure you'll find them useful.
Solution 1: RP Tools
Since you asked for a Windows application, these should fit the most. They're actually five applications that stack with each other. You can combine them to achieve what you need. I'll give a short explanation of the tools. I'll put an asterisk beside the ones I believe you'll need given what you wrote here.
Map Tool(*): Basic tool that helps you building maps and combat grids; You can set up fog of war, and upload your own maps to be even more accurate with the details. I actually set up a dungeon with this once, and my players really enjoyed exploring it with this tool. With a little practice, this is a very powerful tool;
Token Tool(*): With this tool you can import images and put them inside a token you'll be able to use in Map Tool. This means that every monster/NPC/PC will have a custom token, and will be even easier to recognize them if you choose a different picture frame for each one;
Character Tool: You didn't want to have things automatized, so I'm not asterisking this and won't go in detail; Anyway, this is a very nice tool if you want to keep track of progresses or don't want to mess up with stats and so on;
Initiative Tool(*): With this we are going to complete the set of applications you need. It has two inner tools. One to help you run an encounter and one to help you keeping track of players and NPC groups. I'm pretty much sure you'll find it very useful;
Dice Tool: To be honest, I never used this one since we always used real dice. But I guess it's worth trying it if you don't have/can't/don't want to use real dice, since it has lots of useful functions.
Important note: These tools need Java 5/6 to execute correctly. I actually encountered problems with Java 7, so avoid using it and get an older Java version (you can install several versions on your system without corrupting the others).
Download link: http://www.rptools.net/index.php?page=downloads
Solution 2: Roll20.net
After signing in, this website has all the features you need, and even more! You can import images, set up combat grids, manage initiative and so on. Roll20 can also be used to run online campaigns, it has a really nice vocal/video chat functionality, and it's growing every day with new features and a nice community. You should check it out.
So, let's analyze the situation.
RP Tools Pros:
- Runs offline, a painsaver if you can't go online;
- Tools are very easy to use and there are guides on the Internet;
- Very good fog of war management, useful if you have to test assassins, or stealth;
- Token Tool is insanely useful;
- All applications stack very well together.
RP Tools Cons:
- So many applications! It can be very confusing until you get used to it;
- Need older versions of Java.
- You don't need to download anything;
- Simple and straight to the point;
- Rapidly evolving;
- Way better than RP Tools to run online campaigns: it was designed for this.
- It is an online tool :(
- Some features require subscription.
If you are unsure on what you want to use, IMO you should try both of them :)