Not sure if we can call this a bug but anyway:

[GMAK2442]

My HD got defect and when I try to delete torrents so I can download the same torrent again on another disk, Bitcomet jam and I can't even close it with task manager.

[The UnUsual Suspect]

Your disc error should be corrected first, Bitcomet won't be able to delete a file if the harddisk isn't working properly, defective disc can also adversely affect system stability.

You can also delete all tasks by deleting the "downloads.xml" file, it's location will vary depending on the version of bitcomet, the settings used, your version of windows and the user account settings in windows. Windows XP is the last windows version that allowed apps to select where a users data is stored so this wouldn't be complicated if microsoft didn't make it so and to simplify things we've gone to a lot of trouble to make a "READ THIS before posting" topic and posted links to the topic all throughout the forum, yet still it is ignored.