RE: Upgrading Inspiron 1545 from Win 7 to Win 10
This model has not been tested by Dell for W10 compatibility - see this link - http://dell.to/1N2hHIt - hence Dell would not release any W10 drivers for this system model. Now, we could wait and see if Dell would release any W10 drivers. It may or may not be possible. However, a safe bet is that Dell would not release the drivers for an outdated model.
You could try reinstalling the bluetooth / wireless drivers - http://dell.to/1MypgYb - from this link - download and install the drivers in compatibility mode for W7 - http://bit.ly/1Tixfax - see this link on how to. This might resolve the issue, however we cannot assure that W10 would be stable on your system.
I would suggest you to downgrade the OS to W7 for full system functionality - see this link on how to - http://bit.ly/1MeFV1d
Let us know if you have any other questions.