availble space is 46.4 MB, used space is 24.3 GB
Tiny little C drive (25gb) and only 46mb
available.....no wonder your getting a warning. 25gb is small. Are you sure that there is not another available partition on the hard drive. You will find the info in the disc manager I outlined above. If not then do you have another hard drive available? If not do you have an external drive?
See if there are any programs you don't use or want and remove them. See hereDefragClean