Solution for Vista failing when copying files over a network

When copying files over the network with Vista, you may receive one of the following errors during the copy operation, especially while attempting to copy a large file:

There is a problem accessing shared folder path.
Make sure you are connected to the network and try again.

or

Error 0x80070079: The semaphore timeout period has expired.

or

The connection has been lost.


This happens, apparently, because Vista limits the number of half-open network connections that it can make, ostensibly to harden the operating system against attacks. Why it gets in the way of simple file copying, I do not know.

The Solution:

1. Download the "Vista TCP/IP & UAC AutoPatch" from here. If the link no longer works, do a web search for those terms and it should turn up. Note: this is not a file from Microsoft. It's the work of a savvy Windows user who figured out how to uncap the limit on half-open connections by patching tcpip.sys and implementing a few registry tweaks. You should be comfortable with this to proceed, but, if you're like me, you're willing to try anything to fix this crippling problem. The author does allow for the changes to be easily undone.

2. Save any documents that you have open because the patcher will automatically shut your system down when it completes.

3. Extract the zip file and run patch32.bat if you're using 32-bit Vista or patch64.bat if you're using 64-bit Vista. If you don't know, run patch32.bat. Follow the prompts. It'll reboot your system when it's done.

4. Upon re-entering Vista, re-enable User Account Control (UAC). The patch disables it, but it doesn't need to be disabled for the patch to work. I think that the author just has something against it and disables it as a courtesy to you, but your system's security is better off with it on. To re-enable it, find the shield icon in your taskbar (it should be either red or orange) and click on it. Find UAC under "Other Settings" and click the button to turn it back on.

Try your copy operation over again and, hopefully, you won't have any problem this time. If you do or, at any time, you need to undo the change, run the UndoPatch.bat file that is provided with the patch.