Recently some customers reported that sometimes downloads seem to hang at “1 sec remaining” and 99% in the new IE9 download manager.
Actually the files seem to be complete as renaming the “.partial” files seems to work.
There are several things that you can try to mitigate this:
1)Open Internet Explorer (IE) in no add-ons mode and check if that fixes the issue.
To start Internet Explorer without add-ons,
a. Click the Start button, and selectAll Programs.
b. Click Accessories, and selectSystem Tools.
c. Click Internet Explorer (No Add-ons).
2) Anti-virus or Anti-Spyware programs are blocking it. Before downloading anything, ensure you trust the website where the download is from and the download is not containing virus. Disable AntiVirus temporarily, and try to download something. If downloading is working now, it means the Anti Virus application is blocking it, you may contact the vendor of A/V for further help.
3) Ensure you have enough free disk space.
4) Ensure you are keeping the tab which launched the download open. For example, it may be triggered when you are going to a site full of videos, right clicking a video and clicking “Save Target As”, then closing the tab before the download can complete, If you keep the tab open, it will complete successfully.
Edit: This issue was fixed in IE9 security rollup package released on June 14th. More details here: http://support.microsoft.com/kb/2566258
5) Finally, you can rename the “.partial” files which are 99% because actually the files are complete.