To switch off cloud storage and use SD card only in the EseeCloud program for Windows, you can try the following steps:
1. Open the EseeCloud program.
2. Go to the settings/options menu within the program.
3. Look for an option to disable cloud storage or disconnect from the cloud.
4. Once you have disabled cloud storage, the program should now only access the SD card for storing and viewing footage.
Regarding the issue of zero signal strength when trying to preview, it could be due to a poor connection between the camera and the router even though it is only 15ft away. You can try moving the camera closer to the router or ensuring that there are no obstructions blocking the signal. Also, check the camera settings within the EseeCloud program to make sure it is connected properly.