[Argel]

I know you must be tired of these but I think I've been through everything in the FAQ (several times), including uninstall and reboot.

There are no ini files, I have tried removing library1.db.

Error message output below is for two runs, one with library1.db present, having been created when Calibre was run (but the GUI didn't appear) and then again having deleted library1.db just to see what happened:

c:\Program Files\calibre>calibre-debug -c "from calibre.gui2.main import main; main()"
Couldn't resolve property: linearGradient5167
Traceback (most recent call last):
File "debug.py", line 67, in <module>
File "debug.py", line 56, in main
File "<string>", line 1, in <module>
File "c:\Program Files\calibre\library.zip\calibre\gui2\main.py", line 1346, in main
File "c:\Program Files\calibre\library.zip\calibre\gui2\main.py", line 199, in __init__
File "calibre\gui2\library.pyo", line 505, in set_database
File "calibre\gui2\library.pyo", line 127, in set_database
File "calibre\library\database.pyo", line 792, in __init__
File "calibre\library\database.pyo", line 555, in create_version1
sqlite3.OperationalError: table books already exists

c:\Program Files\calibre>calibre-debug -c "from calibre.gui2.main import main; main()"
Couldn't resolve property: linearGradient5167
Traceback (most recent call last):
File "debug.py", line 67, in <module>
File "debug.py", line 56, in main
File "<string>", line 1, in <module>
File "c:\Program Files\calibre\library.zip\calibre\gui2\main.py", line 1346, in main
File "c:\Program Files\calibre\library.zip\calibre\gui2\main.py", line 199, in __init__
File "calibre\gui2\library.pyo", line 505, in set_database
File "calibre\gui2\library.pyo", line 127, in set_database
File "calibre\library\database.pyo", line 792, in __init__
File "calibre\library\database.pyo", line 555, in create_version1
sqlite3.OperationalError: unable to open database file

Sorry if it's something simple I'm doing wrong but I've run out of ideas.

TIA.