The calibre works wonderful in my win7 system, but not that perfect in win8.
And this is what I got when I tried to convert any book.
calibre, version 1.16.0
<b>error</b>

123, 'CreateFile', 'The filename, directory name, or volume label syntax is incorrect.')
calibre 1.16 isfrozen: True is64bit: False
Windows-8-6.2.9200 Windows ('32bit', 'WindowsPE')
32bit process running on 64bit windows
('Windows', '8', '6.2.9200')
Python 2.7.5
Windows: ('8', '6.2.9200', '', 'Multiprocessor Free')
Traceback (most recent call last):
File "site-packages\calibre\gui2\convert\single.py", line 278, in accept
File "site-packages\calibre\gui2\convert\metadata.py", line 236, in commit
File "site-packages\calibre\db\legacy.py", line 465, in set_metadata
File "site-packages\calibre\db\cache.py", line 57, in call_func_with_lock
File "site-packages\calibre\db\cache.py", line 1145, in set_metadata
File "site-packages\calibre\db\cache.py", line 1140, in set_field
File "site-packages\calibre\db\cache.py", line 944, in set_field
File "site-packages\calibre\db\backend.py", line 1357, in windows_check_if_files_in_use
File "site-packages\calibre\utils\filenames.py", line 348, in __init__
error: (123, 'CreateFile', 'The filename, directory name, or volume label syntax is incorrect.')