There are so many software tools,which may enlarge the size of images. but they all will be costly and having some trouble with them. They may come along with big package of software( for eg photoshop) and occupy large space in memory. so it's necessary to have a simple tool to enlarge your images without affecting the clarity. Smilla Enlarger Beta does this.
While using this freeware, you can just open the image and enlarge the particular part of the image. you can also adjust the parameter of enlarged images such as Sharpness,Flatness, Fractnoise , Denoise ,etc. so that it will be nice tool for lite version lovers. Download the software from the link1. For downloading it from Smilla Enlarge use the link2.