The Windows Attachment Manager service can slow the WinZip extraction process significantly.
When you download files from the Internet or receive file attachments via Windows Live Mail, Windows Mail, or Outlook Express, Windows creates an alternate NTFS data stream for the downloaded/received file. This data stream contains Internet Zone information. The information is used by the Attachment Manager to determine how the file should be handled (e.g., whether it should be blocked altogether, or allowed to be opened with warnings, etc.)
Zip files are not considered to be high risk by the operating system (at least, by default). Zip files themselves, then, are not blocked. However, as they can serve as a vehicle for files that are considered high risk and, because WinZip is Attachment Manager aware, it honors the presence of the alternate data stream on the Zip file, if it exists. WinZip passes this information on to Windows for files you attempt to extract. This means that with downloaded/received Zip files, all files you attempt to extract are subjected to additional processing by the operating system, and that files not blocked by Windows, extract with the same Zone information as the Zip file.
To prevent slow extraction:
- Right click the Zip file
- Choose Properties
- Click Unblock
This will remove the zone information and eliminate the Attachment Manager's involvement in the extract process.
If you have any questions, please email Technical Support.
Description of how the Attachment Manager works in Windows...
A quick example of how to unzip with WinZip
How do I compress the contents of a folder and later restore it?