Yesterday McAfee released an update (DAT No 5958) which incorrectly identified a vital Windows XP system file (svchost.exe) as a virus and deleted it, (http://news.bbc.co.uk/1/hi/technology/8636985.stm) resulting in some or all of the following symptoms, amongst others;
1. Repeated rebooting of the system.
2. Loss of Windows “Theme” / “Look & Feel”.
3. Missing “Taskbar”.
4. Inability to use some USB devices.
5. Inability to connect to LAN / WAN / Internet. (Yes, this means no clever network wide solution! 🙁 )
6. Inability to Copy & Paste. (To make things even harder!)
Having tried McAfee’s suggestions and various other options I’ve found the following to be the quickest, simplest, cleanest fix, which also leaves you with the very latest (non-hazardous!) virus definitions installed!;
(This assumes you have access to another, working, computer, which you clearly do or you wouldn’t be reading this!)
1. Download http://download.nai.com/products/licensed/superdat/english/intel/5959xdat.exe (65MB)
2. Copy this file to a CD (a USB stick MAY work if your problem system already has drivers for it). If this system also has Windows XP on it copy the “svchost.exe” from inside “c:\WINDOWS\system32\” (14KB) to the CD as well. Keep both files in the “root” of the CD.
3. Copy the file onto the problem system & then install it. You will likely have to copy the file to the problem system using a command rather than cut and paste… sigh… “copy e:\5959xdat.exe c:\5959xdat.exe” (where “e” is the drive letter of your CD / DVD / USB drive) followed by “c:\5959xdat.exe” would work just fine.
4. After install, don’t shutdown as advised, you need to restore your original svchost.exe file first, to do this either;
i) Restore it from McAfee’s “Quarantine”:
a) Launch the VirusScan Console (Click Start, Programs, McAfee, VirusScan Console).
(If you are unable to launch the VirusScan Console, click Start -> Run & type the command below (including quotes) and click OK: “C:\program files\mcafee\virusscan enterprise\mcconsol.exe” /standalone
b) Double-click Quarantine Manager Policy, then click the Manager tab.
c) Right-click the detection and select Restore.
ii) Copy it from another location:
a) Open a Command Prompt, by typing “cmd” and pressing Enter, either via going to Start -> Run or by pressing Ctrl + Alt + Delete selecting Task Manager (if necessary) and then File -> New Task (Run).
b) Type: copy c:\windows\ServicePackFiles\i386\svchost.exe c:\WINDOWS\system32\svchost.exe and then hit Enter.
(If that doesn’t work then try option “c)” directly below)
c) Type: copy c:\windows\system32\dllcache\svchost.exe c:\WINDOWS\system32\svchost.exe and then hit Enter.
(If that doesn’t work either then try option “d)” directly below.)
d) Copy svchost.exe from C:\WINDOWS\system32 on a similar unaffected system (i.e. they are both XP!) to C:\WINDOWS\system32 on the affected system. You may need to use the copy command again, as above, on the problem system, in which case it would look something like: copy e:\svchost.exe c:\WINDOWS\system32\svchost.exe (where “e” is the drive letter of your CD / DVD / USB drive) on the problem system.
5. Restart the system and you should be all clear to continue computing as normal!
Good luck all! 🙂
(NOTE: If 65MB is a bit too much to stomach, you can replace steps 1 & 3 above with;
1. Download: http://download.nai.com/products/mcafee-avert/wecorl/extra.dat (21.5KB)
2. Repeat 2. as above, but using the “extra.dat” file.
3. Copy it to “c:/program files/common files/mcafee/engine” of the problem system (i.e. using something like: copy e:\extra.dat “c:\program files\common files\mcafee\engine\extra.dat” (where “e” is the drive letter of your CD / DVD / USB drive)