How can I install Revit without enough space on my C drive?

I totally get the space crisis! One thing you can do is download the offline installer to another drive instead of installing directly from the temp folder. That often lets you bypass the space issue on C. You should check Autodesk's support page for guidance on getting the offline file. It also wouldn’t hurt to clean up your C drive a bit!

If you have a secondary drive, consider moving your user folders like Documents, Music, and Pictures there. Go to the properties of each folder, find the location tab, and you can change it to your other drive. This should free up some space on C. Also, running a Disk Cleanup can clear out unnecessary files.

If your C drive is running low on space, it might be a good idea to clean it up. You can use the built-in Microsoft disk cleanup tool, or get a program like TreeSize to see what files are taking up the most space. Also, many installers allow you to change the install path, so check if that's an option for Revit in its manual.