You would need to reinstall Snow Leopard to solve your issue of reinstalling the BT software. However, I think the error means that there is a failure of the BT hardware (module.) You might try running the Apple Hardware Test.
Thank you Kappy for your suggestions. I havn't had a chance to do the Apple Hardware Test yet, but I'm about to print out the instructions and do it sometime... but this info might change the picture: I have 2 external drives; a 2TB (which has OS's in partitions - 10.6.8 & 10.9.2), the other drive is an SSD with 10.9.2 installed. When I was trying to isolate the problem, trying my old & new smart phones (blutooth worked on the phones) with the various operating systems, the bluetooth was broken in both Snow Leopards, but it worked in both Mavericks. That suggests to me that its not a hardware problem since I boot them all through this old MacBook Pro.
I suppose it still wouldn't hurt to do the Apple Hardware Test.
It's possible, then, that the computers running Snow Leopard have a software problem. I would start by reinstalling Snow Leopard on them.
Reinstall OS X without erasing the drive
1. Repair the Hard Drive and Permissions
Boot from your Snow Leopard Installer disc. After the installer loads select your language and click on the Continue button. When the menu bar appears select Disk Utility from the Utilities menu. After DU loads select your hard drive entry (mfgr.'s ID and drive size) from the the left side list. In the DU status area you will see an entry for the S.M.A.R.T. status of the hard drive. If it does not say "Verified" then the hard drive is failing or failed. (SMART status is not reported on external Firewire or USB drives.) If the drive is "Verified" then select your OS X volume from the list on the left (sub-entry below the drive entry,) click on the First Aid tab, then click on the Repair Disk button. If DU reports any errors that have been fixed, then re-run Repair Disk until no errors are reported. If no errors are reported click on the Repair Permissions button. Wait until the operation completes, then quit DU and return to the installer.
If DU reports errors it cannot fix, then you will need Disk Warrior and/or Tech Tool Pro to repair the drive. If you don't have either of them or if neither of them can fix the drive, then you will need to reformat the drive and reinstall OS X.
2. Reinstall Snow Leopard
If the drive is OK then quit DU and return to the installer. Proceed with reinstalling OS X. Note that the Snow Leopard installer will not erase your drive or disturb your files. After installing a fresh copy of OS X the installer will move your Home folder, third-party applications, support items, and network preferences into the newly installed system.
Download and install Mac OS X 10.6.8 Update Combo v1.1.
After I read your last entry with detailed instructions on how to do a reinstall from the Snow Leopard Installer (thats gotta help somebody, if not me someday), it occured to me that the demise of my Bluetooth happened in phases. And when it worked while booted into the SSD, it had still showed in the top menu bar as 'available' while in the original Mac HD 10.6.8, but it was frozen in that OS. The final phase was the squiggle line through the Bluetooth symbol and when you click on it, it says "Bluetooth: Not Available." I just booted into the SSD/Mavericks and sure enough, Bluetooth is now not availble in it either. So it's a hardware problem. I recently upped my memory from 2GB to 8, and this MacBook Pro had never been opened in 5 years: it was very dusty, especially the fans. I vacumed it out as carefully as possible, it makes me wonder if I did something, extra stress on an old creaky system?
So it doesn't seem like a Apple Hardware Test is really necessary (or is it?), I just have to decide if I want Bluetooth enough to get this MBP repaired.
I would mark this thread as solved, but I will wait a bit and see if there's anything else to be said before I do that.
Bless you for posting this; so clear and concise. I am working with an older Mac Pro (1,1) that I bought specifically with the intention of maintaining in an arrested state (new clean copy of Snow Leopard) so that all of my old music making toys can stay active ... I would have been afraid to re/install Snow Leopard if I hadn't read this, and the Bluetooth (Mac, factory) that I installed today that it was not seeing ... is now being seen. Thanks!