I would suggest completely removing all traces of whatever attempted to install, and starting again - from downloading the files all over again. This would include deleting registry entries, if present, and also deleting any local application data in its hidden folder.
To completely eradicate X3:
1. Go to Control Panel>Programs>Uninstall a Program, and if Sonar X3 Producer is present, then delete it through Control Panel. Say 'No to All' if asked if you want to delete other components. Please note that given the install trauma, there may not be anything allowing you to run the uninstall through Control Panel. IF that is the case, you will want to go into C:\Program Files\Cakewalk and if you see a folder called Sonar X3 Producer then delete the whole folder. The x32-bit program lives in C:\Program Files (x86)\Cakewalk, if it was installed.
2. Open Windows Explorer. If you have not altered the default Windows View options, you will not see any hidden folders and such, so you may have to enable Windows to display hidden items. Navigate to C:\Users\'put your user name here'\AppData\Roaming\Cakewalk, and if you see a folder called SONAR X3 Producer delete the whole folder.
3. Now to delete any registry keys. Run Regedit, then navigate to: Computer\HKEY_CURRENT_USERS\Software\Cakewalk Music Software\SONAR Producer. Look for a key called X3, and if present delete it.
4. While still in Regedit, now navigate to: Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Cakewalk Music Software\SONAR Producer, and if a sub-key exists for X3 then delete the X3 key. Please note that this is for x64 Sonar X3. The key for a 32-bit install of X3 would be: Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Cakewalk Music Software\SONAR Producer, and there look for and delete an X3 key, if present.
OK - the above will clean off all traces of an install of X3, allowing you to start over.
I would suggest you use a file download manager to do the Sonar X3 dowloads. Google Chrome has one built-in, and it works well. You MUST temporarily suspend or turn off any and all antivirus software PRIOR to initiating the downloads. This would include Windows Defender as well, if it is used, along with things like Avast, AVG, McAfee, etc. I would recommend you use the above-posted link to check the validity of the download files, using the published hash tag values.
I DO believe your install issues stem from a combination of initially corrupted download files, compounded by attempting an additional install after the partial one(s) had failed somewhere along their way.
Good luck - on a positive note, since you exhibit the kinds of errors associated with corrupted files and not cleaning out failed installs, you will likely be just fine at the end of all of this.
Do not forget to right-click on the installer and EXPLICITLY click Run As Administrator, and also when you finally finish the install and run Sonar for the first time do the same. I actually ALWAYS have Sonar set to run as administrator, which is a check box option in the Properties of the X3 launch icon, under Advanced.
Bob Bone