Wesnoth doesn't start up.

[Zlob]

Hello. I have same problem as here:http://forums.wesnoth.org/viewtopic.php?f=4&t=36608
Operating System: Windows 7 Home Premium 64 bit
Version of Wesnoth: 1.10.1
Everything is same until I remove preferences. Then, I get this in stderr.

Spoiler:

Battle for Wesnoth v1.10.1
Started on Sat Jul 21 13:45:25 2012

Automatically found a possible data directory at C:/Program Files (x86)/Battle for Wesnoth 1.10.1
20120721 13:45:25 error filesystem: Could not open 'C:/Users/Grzesiek/Documents/My Games/Wesnoth1.10/preferences' for reading.

Data directory: C:/Program Files (x86)/Battle for Wesnoth 1.10.1
User configuration directory: C:/Users/Grzesiek/Documents/My Games/Wesnoth1.10
User data directory: C:/Users/Grzesiek/Documents/My Games/Wesnoth1.10
Cache directory: C:/Users/Grzesiek/Documents/My Games/Wesnoth1.10/cache
Checking video mode: 1024x768x32...
setting mode to 1024x768x32
terminate called after throwing an instance of 'boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::iostreams::gzip_error> >'
what(): gzip error

I don't know when the files could get corrupt, because I had a 2 weeks or so break in playing.
EDIT: After I delete cache files, the game starts properly, but laurels around accomplished campaigns are gone.
EDIT2: Thanks for answering. Mass of advices on what I should do is astonishing. Guess I will have to complete campaigns once more.

[JaMiT]

EDIT: After I delete cache files, the game starts properly, but laurels around accomplished campaigns are gone.

The laurels are controlled by the preferences file, which sits in the userdata directory (next to the cache, not in the cache). Deleting just the cache should not remove your preferences. Did you lose your saves as well? If so, then it is likely you deleted all of userdata instead of just the cache (and possibly deleting just the cache would allow Wesnoth to start again).

If you actually need to delete the preferences file, then yes, your laurels will be gone (because you deleted the record of them).

[Zlob]

Yes, I needed to delete preferences. Okay, thanks for answering anyway.