You will need
- - Microsoft Office.
Do not think that only the bulky and slow on lower-end computers Photoshop can cope with the given task. There are a lot more affordable and simple programs that are able to perform this operation is not worse than the glorified and the Almighty Photoshop. One of them is installed by default along with Microsoft Office and is perfect for your purposes. The convenience is that you don't need to download anything and install – if your PC has Word and Excel, in most cases, will Microsoft Office Picture Manager. It is this program you need.
You can find the icon to run the program in "start menu" or start to edit photos in this program in another way. To do this, click the right mouse button on the image file that you want to convert to black and white. In the context menu select "Open with..." and then click Microsoft Office Picture Manager. The program is run, and the added. You can go to work on the chroma.
Find on toolbar button "Edit pictures" and click it. In the right pane, click "Color". You will see three scale sliders which you can adjust such parameters as colour intensity, hue and saturation. All you need to do to turn a photo into a black and white picture is moving the slider on the scale of "Saturation" left until the very end. Photos will be in black and white!
You only have to click the button with the diskette icon to save the changes. However, if you want to save the original file with a color photo, select the menu "File" click "Save as", then save in any folder on your computer and received a black and white photo under a new name.