Don’t Worry…… Partition it to increase the space.
Often we will be running into problems of low disk space in system drive .. even though you allocated 30 GB for it.
Some Free Partition Tools
I have used Aomei Partition Assistant on my Windows 7 PC to increase drive space by 30 GB. It reallocated space from another drive towards the C drive. The entire operation took around 1 hour and no problems were faced.
The tool applies for Windows 7, 2003, 2008 etc.