Every once in a while I have a need to resize a bunch of images and while there are many programs to do it the below is my favorite utility. It always takes me a while to find it through google so posting it here.
You download the PhotoResize400.exe and simply drag and drop files on top of it to resize them. The images will be resized to 400 x Maintain resolution. To resize to a different resolution just rename the file name to match your resolution. Pasting all the options below.
Resizing method PhotoResize400.exe - maximum side 400 pixels. PhotoResize_400.exe - minimum side 400 pixels. PhotoResizeF400x300.exe - frame size of 400x300 pixels. The resulting image width will be smaller or equal to 400 and its height will be smaller or equal to 300 pixels. PhotoResizeW400.exe - width set to 400 pixels. Height automatically computed to keep aspect ratio. PhotoResizeH400.exe - height set to 400 pixels. Width automatically computed to keep aspect ratio. PhotoResizeP50.exe - resize to 50%. PhotoResize400x300.exe - resize to exactly 400x300 pixels. Aspect ratio is not preserved. PhotoResizeD100.exe - resize to 100DPI. Physical size stays the same. PhotoResizeD100T.exe - overwrite the resolution information in the header without touching the pixels. PhotoResizeK20.exe - resize to approximate maximum size of 20kB. PhotoResizeG1024x768.exe - use content-aware resizing to change aspect ratio while preserving content. PhotoResizeA400x300.exe - crop and resize to 400x300 pixels. The central part is preserved and resized while the borders are cropped. PhotoResize400x300x5.exe - extend canvas and resize to 400x300 pixels. The last number (0-9) controls canvas brightness. Additional options PhotoResize400R.exe - process recursivelly all sub-folders. PhotoResize400C.exe - place files to current folder (current folder can be specified in shortcut properties). PhotoResize400S.exe - skip files already smaller than the requested size. PhotoResize400O.exe - do not wait for Enter. PhotoResize400U.exe - skip files already existing in the destination location. PhotoResize400N.exe - sharpen image. PhotoResize400I.exe - overwrite source files. PhotoResize400M.exe - copy metadata. PhotoResize400E.exe - preserve file modification time in addition to file creation time. PhotoResize400A.exe - use arithmetic compression. PhotoResize400V.exe - auto-rotate be EXIF tag. PhotoResize400X.exe - process landscape (width >= height) pictures only. PhotoResize400Y.exe - process portrait (width < height) pictures only. PhotoResize400Q50.exe - set compression quality to 50%.