Category Archives: Windows Vista

Remote Desktop Sessions Pause Or Exhibit Unresponsiveness – Lag Whilst Typing And Session Will Not Accept Mouse Inputs

Remote Desktop Services can be extremely useful, allowing users to access a terminal server or their company desktop computer from another location.  One very common complaint with RDP sessions is screen refresh delays and a delay when typing or trying to click on items using the mouse cursor.  It will appear to most that the session has become unresponsive for a period of 5-20 seconds, after this delay the session will return to normal for a period of several minutes before once again becoming unresponsive.  You may find that this issue becomes more apparent as more users connect to the specific terminal server in question and if all these users utilise several applications (i.e. Outlook, Word and Excel) together.

Causes for poor user experience when connected via RDP are varied but one of the most common is resource exhaustion or contention.  This in turn causes a delay in processing that appears as a pause or unresponsiveness.

Check that your computer or terminal server has sufficient Memory to cope with the current load.

The next thing to verify by using performance monitor is that the PhysicalDisk\% Idle Time is consistently high, that’s correct this should be 90-100% when the server is not very busy.

It is worth running performance monitor using the PhysicalDisk\% Idle Time counter whilst you are seeing the slowdowns, this will help identify if your hard disk or controller are causing contention and in turn the pausing or unresponsiveness.

If you do find that the “%Idle Time” keeps going very low then it’s time to consider some of the options below to help resolve the issue

  • Install a second drive or mirror set, move the Windows Page File to this second disk/array to reduce the load on the drive/array holding your operating system
  • Install additional memory into the computer or server, this will reduce paging to disk and will generally improve overall system performance
  • Migrate to or upgrade your existing RAID controller to a unit that had a Battery Backed Cache (Fast) or Flash Backed Cache (Newer – Faster) to significantly improve performance and alleviate the system
  • Migrate to faster hard disk drives, 7200, 10,000 or 15,000 RPM drives are amongst the fastest.  The SATA interface is slower than the SAS interface but is cheaper.  Try to invest in the fastest drives that you can to future proof the system and avoid future performance issues if you have to scale for more users.
  • Ensure that you have at least 20-25% free disk space on all partitions/drives
  • Defragment all drives on a regular basis to optimise read and write operations
  • A cheap solution for improving disk performance may be to turn on the Hard Disk Cache using “Device Manager” or in the event that you are using a RAID controller without a battery backed Cache module you will need to open the RAID Array Management Software and then enable Disk Cache within the management software as this feature will not be available within “Device Manager” in this instance.  Please note that this does have some risks and should be used with caution, you may loose data in the event of a sudden/unexpected loss of power to the system.  Consider using this option with a UPS and redundant power supplies to reduce the risk of power loss to the system.  As always ensure you have a reliable backup that is carried out at regular intervals.

Example – HP RAID Array Configuration Utility:

Example – Windows Device Manager:

Watchguard – SSL VPN clients cannot resolve internal host names despite DNS servers being configured for the connection

You may find that when you configure your Watchguard XTM Firewall to accept SSL VPN connections that clients can connect to

the VPN and ping IP addresses of internal resources, however you cannot resolve internal hosts even via FQDN using DNS.  You

may also find that when you run NSLOOKUP on the SSL VPN connected client that the  result is your Internet Service Providers

DNS servers rather than the DNS servers assigned via the VPN connection.

 

To resolve the issue you can change your SSL VPN configuration from a “Routed VPN” to a “Bridge VPN”, the routed VPN uses a

virtual IP address pool (192.168.113.0/24) which does not match your internal IP range or the address range of the internal

DNS Servers.  When a Windows client connects to the “Routed VPN” it appears that due to the DNS server mismatch they are not

utilised by the client.

 

When you configure the VPN in “Bridge VPN” mode you can work around this issue, the Bridge VPN configuration allows you to

exclude some addresses from your Windows DHCP Server Pool and add the into them “Start” and “End” IP addresses on your

Watchguard SSL VPN Configuration Page. The Watchguard will now become responsible for assigning these internal IPs to VPN

clients as they connect rather than the Windows DHCP Server.

 

You should now find that when your SSL VPN clients connect that they are assigned an IP address and DNS server that are all

within the existing internal IP range of your network.  An NSLOOKUP should now return your internal DNS server address and

you should be able to ping hostnames and FQDNs that reside within your internal network.

 

Examples:

ping windowsserver

ping windowsserver.exampledomain.local

 

Please remember that the only down side with this configuration is that a “Bridge VPN” bridges to the “Trusted” interface,

this means that the client computer can access any internal resources that they have permissions for by default. A “Routed

VPN” allows you to offer traffic to Optional/secondary networks and gives you more control by letting you lock down access

using “Specify allowed resources”.

Microsoft Windows Vista – SP1 or SP2 and Microsoft Windows Server 2008 – SP1 or SP2 – How to Easily Free Up Some Disk Space

Have you started to notice that C drive is getting a little full or do you just want to have a spring clean, well you may not realise it but when you installed Service Pack 1 or Service Pack 2 onto your Windows Vista or Windows 2008 Server that Microsoft very sensibly backed up all the old system file before replacing them with new ones.

Assuming that you have had Service Pack 1 or Service Pack 2 installed for sometime without issue it may be good to know that you might be able to reclaim some disk space by dumping these obsolete system files.

Simply launch an elevated Command Prompt by right clicking “Command Prompt” and selecting “Run as administrator”.  Once you are in a command prompt simply paste in the following according to the Service Pack you are currently running:

Service Pack 1 you need to paste: VSP1CLN.EXE

Service Pack 2 you need to paste: Compcln.exe

Be patient with these commands they will need time to enumerate a large number of files and could take up to 60 minutes to complete.  Once finished I would recommend a reboot.

With these commands we are telling the operating system to remove any of the superseded service pack files.  If you do not have any files to remove it might be because someone else has already removed them or your computer/server may have already come with Service Pack 1 or Service Pack 2 pre-installed/integrated.

Improve Windows Performance by Enabling SATA AHCI Mode

Probably the biggest bottleneck in most computers these days is the hard disk drive and its interface (SATA).  Depending on the current configuration of your system it may be possible to further improve performance by turning on SATA AHCI mode in your system BIOS and ensuring that your Operating System has support for AHCI enabled.

Here is a brief guide to verify if AHCI is already enabled and if not to ensure that AHCI can be enabled and will work correctly.

Restart your computer and wait for the BIOS Screen to appear, you will need to enter your BIOS Setup Screen.  The Key to enter the BIOS Screen can vary between systems,  “Delete”, “F1”, “F2” or “F10” are some of the most common shortcuts.

Once in the BIOS Screen locate the SATA Controller options and check if the SATA mode is “AHCI”, “Compatible” or “IDE”. The “Compatible” and “IDE” options are usually selected when you are using a Legacy Operating System that does not have native AHCI and/or SATA support.  The trade off with these modes is that the operating system is unlikely to be able to take full advantage of all the features of your SATA Hard Disk to improve system performance.

If you find that your system is set to “Compatible” or “IDE” mode then don’t change anything just yet.  First we need to make sure that your Windows Operating System has AHCI support installed and active so lets exit the BIOS without making any changes and boot back into Windows.

Once you are back in Windows click on the “Start Menu” and then in the “Run” or “Search” box you need to type “regedit.exe”

You will need to locate the following two registry keys

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Msahci
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\IastorV

Under both of the listed registry keys above you will find multiple values, amongst these you will find a “REG_DWORD” value called “Start” and these both need to be changed from “0” to “1” to tell Windows that we want these additional AHCI controller drivers to be loaded at startup.

You may ask yourself why these are not enabled by default, Windows actually disables any unused drivers to speed up the Windows Startup process.  In this instance we just need to turn these two back on to accomplish our ultimate goal.

Now that we have AHCI support enabled within Windows lets reboot the computer once for these Registry changes to take full effect and to give Windows a chance to initialise the AHCI drivers.

The final set of this process is to restart the computer one last time and enter the BIOS screen again by using the process above.  Once in the BIOS locate the SATA Controller options and change the SATA mode to “AHCI”.  Remember to select “Save Changes and Exit” so that everything takes effect.

You should now find that the system boots back into Windows, the first boot may be a little slower than usual while the operating system re-detects your Hard Disk Drive.  Subsequent startups should be significantly faster.

If you have any issues booting back into Windows after making the switch to “AHCI” then simply go back to the BIOS and revert your SATA mode to its previous state and you will find Windows boots as before.