Category: Operating systems

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Operating systems

Windows 7 empty recycle bin “hanging” with a lot of files

I was just cleaning up a directory path and had over 1GB and several thousand files in my recycle bin. About 5 minutes after selecting “Empty Recycle Bin” I still hadn’t even got as far as the prompt asking to confirm the delete. After some system monitoring I saw that Microsoft Security Essentials was attempting to scan the files. After temporarily disabling real-time protection the prompt immediately appeared and the bin emptied within 10 seconds or so.

Rather interesting that they scan files that are about to be deleted. The .NET FileSystemWatcher has a deleted method as does the underlying Win32 API so it’s not hard to detect.

Categories
Linux Operating systems

Rasberry Pi initial configuration

Posting my initial Raspberry Pi configuration steps to enable SSH / FTP / VNC and Wifi to a WPA2 access point in case it’s of use to anyone else getting started with the Pi. WPA connection is automatic, I’ve left VNC manually started to save resources when not in use, it can be started via SSH or the console using the following command:

vncserver :1 -geometry 1024x768 -depth 16 -pixelformat rgb565

# loaded debian6-19-04-2012.img to SD card
# expanded main partition using gparted on another machine
sudo /boot/boot_enable_ssh.rc
uname -a
# Linux raspberrypi 3.1.9+ #90 Wed Apr 18 18:23:05 BST 2012 armv6l GNU/Linux
sudo dpkg-reconfigure tzdata
sudo nano /etc/dhcp/dhclient.conf # set host-name
sudo apt-get update
sudo apt-get upgrade
sudo apt-get install ca-certificates git-core proftpd tightvncserver
sudo wget http://goo.gl/1BOfJ -O /usr/bin/rpi-update
sudo chmod +x /usr/bin/rpi-update
sudo rpi-update # ignore error about libvchiq_arm.so
sudo reboot
uname -a
# Linux raspberrypi 3.1.9+ #159 PREEMPT Wed Jul 11 19:54:53 BST 2012 armv6l GNU/Linux
wpa_passphrase <SSID> <Passphrase> # copy hex from psk= and paste into <PSK> below
sudo nano /etc/network/interfaces
# append following to bottom:
auto wlan0
iface wlan0 inet dhcp
wpa-ssid <SSID>
wpa-psk <PSK>
Categories
Operating systems

VMWare shared serial ports with Windows XP

Recently the serial communications ports on a VMWare machine I had setup for embedded development stopped working. I believe what triggered the problem was booting the VM while another VM had the same physical serial ports locked and it appeared to get the XP device stack into an odd state. I found that by deleting the serial ports under hardware manager and performing a reboot it cleared the problem.

Categories
Operating systems

Windows domain slow login

Today I was creating a new VMWare virtual machine to install some embedded development tools I need for an upcoming project but don’t use often enough to have cluterring my main machine. The first login after adding the machine to the Windows domain took approximately 20 minutes. It reminded me I’d had the same problem a few years ago and the problem can occur when the machine is set to use an Internet DNS server rather than the DNS server for the local domain. Adding the local domain DNS server as the first priority DNS server for the network adapter corrected the problem.

Categories
Operating systems

Vista network changes for older devices

Recently I installed Vista x64 and had some hassles with some older gear caused by changes to the default behaviour of the TCP stack. An HP Colour LaserJet 4550N would occasionally print a page of junk, I had a few problems with a Cisco 827 ADSL router corrupting some packets and also had file corruption problems using wireless networking to an XP Toshiba laptop running over a WLAN.

The following were the things I did to turn off the new features which solved my problems. I started by turning off SMB2 by inserting the following registry entry:

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters]
“SMB2″=dword:00000000

Under device manager I disabled the following features for my network adapter:

IPv4 checksum offload
TCP Checksum Offload (IPv4)
UDP Checksum Offload (IPv4)

From an elevated command prompt ran the following to turn off TCP auto-tuning features:

netsh interface tcp set global autotuninglevel=disabled
netsh interface tcp set global rss=disabled

Then I typed ‘OptionalFeatures’ in the Windows start search box and turned off ‘Remote Differential Compression’