I've searched through the forums (and Googled) and found a lot of people having problems with buffer overflows in Internet Explorer. I had those, too, but after running Virus Scan and Malewarebytes the trojan was supposedly removed.
Unfortunately, I now cannot open any Excel files and get the problem in C:\Program Files\Microsoft Office\Office10\EXCEL.EXE. I have all current Windows Updates and scans find nothing wrong. I'm using XP Pro with SP3. Is there anything else I can do or would uninstalling/reinstalling cure the problem?
Buffer Overflows are usually a bad behaving program because the programmer didn't include some type of error checking for data being passed into the program. Chances are you have a plugin or another program that is loading with Excel causing the problem.
The easiest fix to make sure it's not Excel is to use the detect and repair option in the Help menu of Excel. This is basically the same as reinstalling over itself and correcting missing/incorrect files or settings. It's pretty fast and shouldn't take more than 2-3 minutes.
Make sure you have the latest Service Pack for Office. Some bugs have already been found and fixed. Windows Update won't update Office unless you have Microsoft Update.
Well, when I tried detect and repair the buffer overflow warning came up again, so I wasn't able to do it. My Office products were up to date. I did the Microsoft Update and after restarting the problem persists. Anything else I can do?
You can disable Buffer Overflow protection by doing the following:
Open the Security Center. In the bottom left, click "Advanced Menu". If it says Basic Menu at the bottom, you are already in the Advanced Menu. On the LEFT side, click Configure. Choose the "Computers and Files" section. On the Right side, click on the "Advanced" button in the Virus Protection section. make sure "Real Time Scanning" is selected on the left side. Then uncheck "Enable Buffer Overflow Protection" Click OK.
Sorry, what I meant was that after I disable overflow blocker, run the repair, and re-activate the buffer overflow blocker the problem is still there. Basically, the repair tool didn't fix the overflow problem. Excel does run when the overflow blocker is disabled.
I know that on a basic clean install of Windows and Office 10 (Office XP) that the buffer overflow protection does not trigger. What this means is Office is damaged (not likely in your case as you did the repair/reinstall) or you have another program that tries to load a module into Office/Excel. This does not have to be a virus, but any program that is behaving badly due to a programming error.
If it were my PC, I would try for the full uninstall and reinstall. I would also be sure I updated to Office XP SP3 to make sure I was fairly up-to-date.
If after all of this the problem still exists, you may have to get along with just leaving the Buffer Overflow protection disabled. If you really want to find out what's causing the error, logs of the crash (if there is one) or an examination of what is starting up with or modifying Excel would be needed. This is generally more advanced repair that is beyond most normal PC users.