[Osiris]

A Windows Vista bug that is causing file transfer to slow down has been causing much frustration for many users. A discussion about this problem has been active on the Microsoft Support forums, which you can find here. Although this bug has been around for quite some time and is becoming a bigger problem each day, Microsoft has yet to issue a public release and will require you to contact them directly in order to receive the fix. You can find this bug listed in their database as entry KB931770 with details on symptoms and how to contact them.
However, I have found many other ways that will allow you to quickly fix this bug. I’ve ordered them from “most likely to work for you” to “least likely.” Many who have encountered Windows Vista problems will know that one try is usually not enough.
Method 1 - Download the fix from somewhere else:
I have no idea why Microsoft would require you to contact them to get the fix. Who knows when they will reply to you. Luckily, Hotfix has the files for the fix available for download:
32-bit Windows Vista
64-bit Windows Vista
Method 2 - Use Total Commander:
A Neowin member claimed that this program managed to speed up file transfers. The program he used was called Total Commander, which can be downloaded here.
Using it is pretty straight-forward if it’s only for the purpose of speeding up file transfers.
Select the directory from the drop down menu in the top-left corner and just drag and drop. When a prompt window comes up, just choose OK and the transfer will proceed.

This fix will most likely be included in Service Pack 1. No word yet as to when the pack will be released.