Windows – Changing running application’s icon in taskbar (not pinned icons)

The problem is that the pinned application actually starts another process (which is not pinned). This often happens with applications that spawn a 64bit version of itself after they were started.

Sometimes it helps to unpin the application you have on your task bar, right-click the new task and select "Pin this program to task bar".

FYI: There's a bug report for Chrome on exactly this issue. When I looked into this issue myself a couple of months ago, it seemed like it is generally an application issue (not a general Windows issue). So for every application I use that has this problem, there are usually bug reports about it (FileZilla, Eclipse, ...).

Have you tried running a memory test on the RAM for that machine, I recommend creating a boot-able CD or booting from a USB key drive with Memtest 86+ version 4.20 to test the RAM on the machine. I have seen weird random issues like this in the past and it was a memory issue.You can download the free utility from http://www.memtest.org/. Other then that, I understand update the Video driver but you could also try updating the Chipset driver if you haven't already done so. Then look at updating BIOS for that machine. That being said definitely run the memtest first because if the RAM does have problems, it is likely other programs and installs will also have problems.

I just did some Googling that might be helpful, if my previous suggestions don't work out. Check out this URL from Microsoft Answers, it has a lot of great suggestions to narrow the scope of the problem http://answers.microsoft.com/en-us/windows/forum/windows_7-desktop/windows-7-taskbar-icons-disappear/1ae80c85-04fc-4bef-8a1f-56ee4dc154c5

I have also pasted a screenshot that might be helpful, notice the check box I have set at the bottom of the screenshot regarding inactive icons. Perhaps your icons are disappearing when Windows decides they are in active. I know this mainly pertains to the notification area of the task bar and it might be a long shot, but I thought I might put it out there just in case it helps.

Cheers