Explorer has stopped responding

I put together a system for a friend of mine back in 2011, it's got these specs: Asus P8H61-M LE, i5-2500 3.3Ghz cpu, 4GB ram, Western Digital 1TB Black, Windows 7 x64 Home and it's been working fine up until the last couple weeks when the system started throwing "Windows Explorer is not responding" messages and Explorer keeps having to be restarted. This happens when doing any number of things: opening files, printing and sometimes just working in Word or Excel and this message pops up.

When I look at the system application log the message is "The program Explorer.EXE version 6.1.7601.17567 stopped interacting with Windows and was closed. To see if more information about the problem is available, check the problem history in the Action Center control panel.
Process ID: e8c
Start Time: 01cfbba6ad1bcd48
Termination Time: 0
Application Path: C:\Windows\Explorer.EXE
Report Id: f0091a18-279b-11e4-ae60-f46d041fe5ed"

There are any number of threads on Microsoft's website as well as here about this problem but nothing that anyone has posted seems relevant to this particular situation. In some cases it was some software service from third party software but nothing like that has been installed. Since it seems like a good half of people with this problem have or have had some kind of virus or malware infection I tried these things first: in-depth scan with Eset Endpoint 5.0.2229.1; threat scan with Malwarebytes 2.0.2.1012; scan with Spybot 2.4; scan with Malwarebytes anti-rootkit tool; ran the system file checker tool and it didn't find any corrupted or changed system files; ran Rkill; Temp File Cleaner; AdwCleaner and none of these found anything other than a few tracking cookies. I also ran chkdsk and this disk appears in good condition and no problems were found; I also installed Seagate Seatools for Windows and did a SMART and short disk test and both passed.

Does anyone have any suggestions about any other steps to take to fix this problem?

- Norm

For anyone who happen to come across this thread; I kept trying various removal tools on the system and one of the last three that I tried: Temp File Cleaner, AdwCleaner and Junkware Removal Tool apparently was able to remove whatever was causing the problem and after that Explorer stopped crashing and restarting. So at least in this instance the problem was Malware related.

- Norm

Hey Norm, I'm glad to hear that you've found a solution to your problem, and thank you for sharing it with us.
You're right, it usually is something that modified the explorer.exe itself, some third-party software such as QTTabBar or those start button changers. Other than that it's possibly malware - and turns out that not every scan tool is perfect, and different ones work in different cases.