Help! Firefox is [stalling/displaying images extremely fast/won't open at all/takes 100% CPU usage]. Help! Thunderbird is [stalling/not opening/locking up/taking 100% CPU usage/displaying time-out errors instantly without checking my email account]. Help! [other app] is acting weird.

Most issues arise when these programs are run in multi-core processing environments (such as AMD X2 processors, Intel Core Duo, and even Pentium 4 Hyperthreading). To fix this problem permanently, make a backup copy of the .exe in question, and then use ImageCFG to set the affinity to a single processor/core. This should work on nearly every application. I'm sure there are plenty of other applications that aren't multi-core aware, and this will help you fix them, or at least assign them to other cores!

  1. Download ImageCFG from the ImageCFG page. Save ImageCFG.exe to the root of your system drive (%systemdrive%), for readability/compatibility purposes. Alternatively, you could permanently install it as a system command by putting it in \Windows\System32.
  2. Open a command prompt window: Start > Run > cmd.exe
  3. Type all of the following, pressing enter after each line (substituting any paths that may be incorrect on your system):

    4. %systemdrive%
    cd \
    copy "%programfiles%\Mozilla Thunderbird\thunderbird.exe" "%programfiles%\Mozilla Thunderbird\thunderbird-old.exe"
    copy "%programfiles%\Mozilla Firefox\firefox.exe" "%programfiles%\Mozilla Firefox\firefox-old.exe"
    ImageCFG -a 0x1 "%programfiles%\Mozilla Thunderbird\thunderbird.exe"
    ImageCFG -a 0x1 "%programfiles%\Mozilla Firefox\firefox.exe"

    You will need to make sure that "%programfiles%\Mozilla Thunderbird\thunderbird-old.exe" goes on the same line as copy "%programfiles%\Mozilla Thunderbird\thunderbird.exe" as the line(s) may get split or wrapped in your browser. If there is any confusion, click here for a plain text file that will probably not wrap in your browser. If it does wrap, screw your browser!