I had a nasty little file download itself onto my desktop but not properly. As a result, it didn't work. Yet every time I hit delete an error message said, "Cannot delete file: Cannot read from the source file or disk". The file had 0kb of memory, the file name was incomplete, and there was no file extension. It wasn't a virus or malware - I scanned to be sure. I was using Windows XP. Here's a quickie on how I fixed it by deleting the folder that contained the file. (Legal blah: back up your data, read the instructions, read other people's instructions, I take no responsibility for any data, monetary or other loss, this is just a story of my personal success...)

1. First I found the correct folder address by using Start>Search. I needed the correct address in order to locate it during the next step. In my case, the file was located at C:\Documents and Settings\MY NAME\Desktop\divx-501.vo.llnwd.net

2. I opened the command prompt by clicking Start>All Programs>Accessories>Command Prompt

3. I changed the directory from "C:\" to "C:\Documents and Settings\MY NAME\Desktop" by typing the following and hitting Return (note that "cd" means "change directory"):

cd C:\Documents and Settings\MY NAME\Desktop

4. I deleted the folder the file was contained in by typing DEL followed by the stupidly long name of the folder:

DEL divx-501.vo.llnwd.net

5. The Command Prompt asked whether I was sure? I typed Y, and hit Return. This is what it all looked like (click to zoom):



Returning to the desktop, I then tried to delete the folder containing the evil file, and this time, it deleted! Hooray. (If the file had been locked by explorer, which it wasn't because I checked, you also need to switch off explorer.exe while you use the Command Prompt. Look that up if you have no idea what I'm talking about.)