Help With Missing EXE File Association

So today, I opened Outlook and downloaded my email messages. Every single day, I get a report from one of my staff in Excel and today – for no reason I can think of – I cannot open the Excel file attachment. Since I’m a bit ‘techie’ I was already thinking that I probably have to reset an exe file association on my Windows registry.

Most programs or documents can only be opened or used if your operating system knows how to launch it. In the example above, the Excel document had a *.xlsx extension, which meant that Excel 2007 is required to open it.

To be more precise, Excel.exe is required to open the *.xlsx worksheet that was sent to me and for some reason that did not work anymore, so here’s what I did to troubleshoot this problem.

1)   Check that it’s not just that particular file that has the problem. Before I went and fiddled with file associations and the Windows registry, I wanted to make sure it was a general problem and not just because that attachment got corrupted or infected with a virus. So I downloaded the file, ran a virus check on it and double-clicked it. That did not work.

Furthermore, when I tried to open Excel reports from previous days, which I could open before, they would not launch either. So I was sure at this point that it was more an incorrect or missing file association issue.

2)   Next, modify the Dynamic Data Exchange (DDE) settings in Excel. Based on what I saw on some Excel forums, I tried to do the following.

• Close the e-mail message.
• Open MS Excel.
• Click the Microsoft Office Button, go to Options, and then click Advanced.
• Select the General tab and then clear or un-check the option Ignore other applications that use Dynamic Data Exchange (DDE)
• Click OK.
• Close MS Excel.

For added measure, I even rebooted my PC after this but this did not work for me either!

3)   By now it was obvious that there was an exe file association missing in relation to Excel. So here’s what I did. (Mind you: always back up your Windows registry before you make any changes!)

• From the Windows Start menu, click Run.
• Type regedit and then click OK. This will open the Registry Editor.
• Now go to this location:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.xlsx

(or whatever the file extension you are having problem with)

• Click the OpenWithList folder.
• Right-click a and then select Modify.
• Under Value Data, indicate the EXE or program that should be used to open the document you want.
• Click OK and then exit the Windows Registry.

After the above I restarted my PC and the problem was solved!

What are the Common Errors Caused by Csrss.exe Virus?

Firstly, please note that the csrss.exe file is a legit and crucial Windows system process. For this exact reason, hackers and malware creators have decided to use this process name to pretend that it’s part of your system.

As a virus, the csrss.exe file can wreak untold damage on your PC; as a Trojan, it can sneak into your PC and retrieve all your private and important financial information.

Here are two basic facts you need to know.

Fact 1: The csrss.exe file resides in your C:\Windows\System32 directory.

Fact 2: The csrss.exe file is NOT a very big file and utilizes minimal CPU memory.

If you see this system process as not meeting the above two criterion, it’s mostly likely a worm, virus or Trojan and removing csrss.exe should be your first course of action.

Csrss.Exe Common Problems

The following are some of the usual errors caused by this malware.

STOP 0xC000021A error.

This error is generated when Windows detects that the (real) csrss.exe file has stopped. One of the reasons this may have occurred is when the file has been corrupted by the ‘fake’ csrss.exe.

High CPU Usage.

When you PC slows down all of a sudden, open Windows Task Manager and go to the Processes tab. Check that the csrss application is not hogging your system’s resources. (Usually this will show that it’s using 90% to 100% of your CPU).

Browser pop-ups and/or redirections.

As a Trojan, csrss can redirect your online efforts by offering pop-ups that have absolutely nothing to do with what you are viewing or sending you to lottery, casino or even adult-related sites.

Computer freezes and crashes.

As a virus, csrss can cause your system to crash completely, causing you to lose valuable files and documents.

How to Get Rid of Csrss.exe Errors

If you think your PC has been invaded by this virus or Trojan, it is of course in your best interest to apply the following csrss.exe removal instructions right away.

• Run anti-spyware and anti-virus software to seek out the fake system application and remove it.

• Run a registry cleaner to remove any remnants of the deleted virus or Trojan from your Windows registry.

• You can edit your corrupted user profile to remove csrss.exe errors. Why this solution? Worms, viruses and Trojans come from somewhere. Try as you might to avoid ‘dubious’ sites and no matter how careful you are in downloading stuff from the internet, some of these resources may have been to source of the problem and it came through your user profile on your system.

To get rid of the virus or Trojan, you need to address the corrupted profile first because each time you enter your Windows system using this profile, the fake csrss.exe file is activated.

• And the most painful solution… back up your important files and documents and reformat your hard disk before installing Windows again. (Note: this mostly works only if you do a FULL reformatting and not just apply the Quick reformatting option. Sorry…)