If you have trouble attaching your logs to a thread, here is a pictorial guide to help you.
I'm using Windows Vista so it will look slightly different for XP users, but the same rules apply. I have used a HijackThis log as an example, but it works the same for any type of log.
Note: There are minor changes since I have written this tutorial/guide. The .log and .dmp file extension have been added and are possible to upload, so some of the screens will look slightly different, so therefore it is no longer mandatory to save your log as a .txt file.
1. Save the log(s) as .txt files.
Once the log has come up, click File > Save As and select Text file (.txt) from the drop down list. This is now optional because the .log file extension has been added to the upload list, which is what HijackThis uses as its logs file extension.
2. Post a new reply and click Manage Attachments
The Manage Attachments button is shown blue here, and is located just under the box where you type your reply.
3. Browse for the log
Click Browse and find the folder where you saved the log file, then select the file and click Open. You have to do this individually for each log, you cannot do more than one at a time.
4. Upload the log
Click Upload to upload the log to the server. The words "Uploading attachment" will come up until the log is attached, then they will be replaced by a list of your attachments.
5. Close the upload window
Click Close this window to finish attaching the log. There will now be a list of your attachments above the Manage Attachments button.
You've now finished uploading your attachment(s) and you can post your reply if you have finished typing your message