When you install a Redgate product, temporary installation files are extracted to the location defined by the %TMP% environment variable. You may want to extract the temporary files to a different location if you do not have enough space in the temporary directory. To do this, run the installer from the command prompt and use the temp argument to specify a different location. For example:

C:\>SQLToolbelt.exe temp D:\Testing

The temporary files will be extracted to D:\Testing and the installer will launch using those temporary files.