Redstick
Abacab mentioned - save the project files with 8 or fewer busses but  the only save options I have are Normal or Cakewalk Bundle, not 8 or 10 Busses ...

Did you try this yet?  First re-configure the project, and then save as? 
 

To open this file it must be re-configured and saved with a Cakewalk product that supports the configuration.

 
The busses are something you created, and the file format really has nothing to do with that. It just saves the project the way you configured it.  As an experiment, delete all of the busses except for the master bus, and then route all tracks output to the master bus.  Save that as a copy of the original project, and see if that opens.
 
 

abacab - I re-configured my project and did a Save As and still the only 2 options are Normal or Cakewalk Bundle

Redstick
abacab - I re-configured my project and did a Save As and still the only 2 options are Normal or Cakewalk Bundle

Those are the only two options available to save as.  Choose either one.  The file type and has no relationship to the project configuration.  It is only a container for the project data as it is.
 

GTPro3 has 8 subgroup buses and 2 aux buses = 10 buses
 
In GTPro3 you cannot delete or remove any tracks or buses because they are  hardwired into the program, so Sonar Home Studio will most likely remove the last 2 buses when opening one of your projects for the first time.
 
I would "save as" a normal project, with each project saved into it's own properly named folder, making sure that "copy all audio with project" is checked, and in the settings make sure that "use per project audio folders" is also checked, bundle files are more risky to use because if the file becomes corrupted you lose all of your audio along with it.
 
 

Redstick, were you using any VST plugins with Guitar Tracks Pro 3?
 
If NOT I can help you get GTPro3 running on a windows 10 machine.

Strryder
 
get GTPro3 running on a windows 10 machine.

It sounds like that may be the only option remaining.  If you read post #5 above, Home Studio refused to open the project due to the bus count.
 

msg Audio buses utilized by project(10) exceed maximum allowed(8).

It's not hard to get GTPro3 running on a windows 10 machine, the old VST adaptor doesn't work, so I un-install it before opening GTPro3 for the first time.
 
Both the really old Cakewalk DX plugins, and the GT:FX automatable DX plugins work and sound just fine.
 
I can type out a step by step for you.

Ok guys, first you need to know the extent of my experience with GTP3 (VERY limited)
- The only way I've ever used GTP3 is to simply record our jam sessions
Open a new project - deselect 'Metronome during recording' and 'Accent the first beat' buttons, select the 'R' for record and press Record.
- I've recorded multiple tracks on some projects. Mute the 1st track, select 'R' record on a second track. Listen to the 1st track via headphone while recording the 2nd track (I found out the hard way if you don't use headphones you are re-recording the play-back onto your 2nd track(sounding kinda messy). Using headphone eliminated this ...
- Never done any post-production, now that I'm retired I planned to start learning how ...
- Had to upgrade PC from XP to Win 10, hence the problems/issues I'm having
- My Goal is to find a product that will read/run my GTP3 files on win 10, I've read GTP3 is not compatible with win 10 so I've been looking for a Cakewalk product that is compatible with win 10 and can read my GTP3 files.
It's my understanding that Sonar will accomplish this?
- Once I confirm or locate a package that will do this I planned to start learning how to do some basic post-production work to clean-up our recordings and maybe add some enhancements.
 
Strryder - I like your suggestion. Maybe I could (get GTPro3 to run on Win 10) I'm very interested in your step-by-step instructions. 
If I get this accomplished I wonder if I should upgrade to Sonar or continue with GTPro3 on Win 10? I downloaded Sonar Home Studio for Free.
 
As always guys I really appreciate your help.
This past Friday is the 1st time I haven't recorded our jam sessions in a long time and everyone was a little disappointed. We like to hang out after the sessions, listen to the playback and critique ourselves or be amazed that we sounded better than we thought :-)
 
I anxiously await your comments ...
 
 

Redstick
 
Strryder - I like your suggestion. Maybe I could (get GTPro3 to run on Win 10) I'm very interested in your step-by-step instructions. 
If I get this accomplished I wonder if I should upgrade to Sonar or continue with GTPro3 on Win 10? I downloaded Sonar Home Studio for Free.

 
I would follow up on the suggestion to get it working in Win10, especially for recovering your old sessions.  Unfortunately there are no Sonar upgrade options available at this time, other than Home Studio.
 

 
As always guys I really appreciate your help.
This past Friday is the 1st time I haven't recorded our jam sessions in a long time and everyone was a little disappointed. We like to hang out after the sessions, listen to the playback and critique ourselves or be amazed that we sounded better than we thought :-)

In the meanwhile, you can always record your new sessions in Home Studio!
 
Start with a blank project:
 
1. Insert an audio track.
2. Select the audio input that you are plugged into.
3. Select the output that you want to hear the track playback on.
4. Click the track's 'Record Enable' button.
5. Click the track's 'Input Echo' button if you want to monitor the input during recording through the computer, if you are not already doing this externally.  You probably don't want to do both at the same time due to latency of the signal through the PC.
6. Check your input levels.
7. Hit record and go!
 
The details are in the 'Help > Getting Started Guide', Tutorial 3, 'Recording vocals and musical instruments'.

If Strryder can get you up and running with GTP3 on Win 10, that is best case. Below is more of another option should it come to such.
 
I am trying to remember, but doesn't GTP3 save files as *.wrk? And also save all audio in the (Global) Audio folder?
 
In a worst case scenario, you could manually import projects (by track) into a new Home Studio Project, but the only way to do so would be to know what audio files go with which project. Does anyone know if ProjectScope taps into wrk (or even cwb) files (I didn't install it on my new machine)? If so, that will allow you to look at a project file and see the associated audio tracks. From there, in a new Home Studio project, you can import audio into each track.
 
If these are not complex, you can forego the above and simply import the audio from your global audio folder willy nilly (or use the browser to listen to them from within Home Studio or even Windows first). If you have GTP3 on an XP machine, it may also be simpler to look at what audio goes in which project.