Except some programs like command promt, regedit,Symmantec Anti-Virus and Windows xp games, I can not start applications including windows explorer, my computer, control panel, System Restore, iexplorer, office etc. The problem started 15th of October on three computers at the same day. One of them is an Acer laptop, other are Dell Desktops. The desktops are connected through LAN but the laptop was at a totally different place where a connection could not be established. The other computers on the LAN are clean (around 15 computers).
Here's the thing; The desktops give an error message at the windows startup saying that "the instruction 0x000.. at memory address 0x00.. could not be read" but there is no such message on the laptop. I have checked the computers for viruses with both Symmantec AV and F-Prot (both updated) but that was negative. I ran "sfc /scannow" and "sfc /scanonce" from command prompt and also "FIXMBR" through recovery console which did not solve the problem and I fixed the registry using "exefix.reg". I tried repairing Windows with the CD but that ended up with a new installation because the Windows Setup stopped responding for a very long time and I could not step back. Now two of the computers work fine after the re-installation, but I had to format the hard drive. There is still one desktop to fix and I really don't want to re-install the OS, so I am awaiting comments.
By the way, I can run process explorer (using command prompt) so I can see which processes are running. There is nothing unusual except I can see that when I start an application, "dwwin" is attached to that application and both are shut down in 1-2 seconds.
Thanks in advance,
M. Taylan Oztek