Monthly Archives: December 2010

Windows XP mode could not be restored because of either host processor mismatch or lack of hardware assisted virtualization support in the system

Computer Aid Posted on by

Windows XP mode could not be restored because of either host processor mismatch or lack of hardware assisted virtualization support in the system.

That is the message I got when I start XP mode on a W7 system… after I made a huge number of changes to a system (while fault-finding).

Since I had updated the BIOS, then that was the first place to look.

Sure enough, the Hardware Virtualization had been switched off during the update.

I switch it back on, restart the PC, and promptly got the same error!

OK a search on the net quickly shows that the hibernation file can get corrupted (which is possible after all the work I had done on this system).

so I delete:

C:Users{User ID}AppDataLocalMicrosoftWindows Virtual PCVirtual MachinesWindows XP Mode.vsv

But I still get the error.

I go back into the BIOS, and while looking the the VT option, I notice a little message on the right side of the screen:

You must power down the system for settings to take effect.

What! I’d never seen that before.

It seems strange to actually power off the system (rather than just do a reset)… but it actually worked!

Switching hard drive from IDE mode to AHCI mode (Vista and Windows 7)

Computer Aid Posted on by

Now most PCs now ship with Windows 7 installed on a drive thats in AHCI mode.

Usually because there can be some potential speed benefit.

But occasionally, an ignorant technician will install W7 with the drive set to IDE mode.

I recently needed to take an existing installation of Windows 7, and in an attempt to improve performance, I wanted to change the drive mode from IDE to AHCI.

I know W7 has native support for AHCI, but before jumping across, I decided to do some research first.

It turns out that W7 actually doesn’t automatically switch to AHCI mode once the hard drive has AHCI enabled in the BIOS.

The first step is to actually go into regedit, then look for:

HKLMsystemCurrentControlSetservicesMsahcistart
HKLMsystemCurrentControlSetservicesIastorvstart
Change the start value to: 0 (ie zero)
write down the original value… just in case.
Close regedit, then restart the PC.
While restarting, enter the PC BIOS, and change the HDD setting from IDE to AHCI
W7 will then start using the drive in AHCI mode.

stop 0x000000EA nv4_disp.dll

Computer Aid Posted on by

Customer has a faulty PC, she gave up on it when she took it back from a repair shop, and it immediately showed a blue screen of death (BSOD).

In disgust, she put it away in a cupboard, and purchased a new PC.

When the new PC started having some problems after a few months, she brought both PC to me for fixing.

I start the older PC, and it seems to start normally.

I then run a test to strain the video card and CPU, and within 2 minutes, I get the blue screen:

stop 0x000000EA, nv4_disp.dll, etc etc.

Well, it seems obvious: NV = NVidia = Video card fault

I remove the video card, activate the onboard Video (also NVidia!), and download the right drivers.

I then restart & run the test again… and this time it runs for over an hour without a problem.

Some video cards are just not made to last.

Failure to display security and shut down options (faulty WD5000AADS)

Computer Aid Posted on by

Another strange problem with an almost-new PC.

Another high-end PC, that was taken back to the original manufacturer (a long distance away) twice… first to fix a faulty video card and power supply, then they are unable to fix this strange computer slowdown.

The PC uses an Intel mobo, a quick, late-model NVidia display card, a quad-core intel CPU, a WD5000AADS drive, W7-64bit, and a good power supply.

Its only got WoW and Norton running on it.

Everything is less than 6 months old, so there shouldn’t be any problems.

Whats unusual, is that the system boots normally, and at some point, will suddenly start running very slow…

I also note that the hard drive light is on – solid, while the slowdown happens.

The only other symptom is that the PC is “usually” very slow to shutdown… about 5 minutes… where I would expect about 10 seconds!

So, my first guess is that its a hardware fault.

I run various RAM tests (including the built-in W7 RAM test)… no fault after an overnight run.

I look at the hard drive SMART settings: everything looks normal… a clean bill of health.

Next: stress test the Video card and the CPU… but the stress test runs normally.

OK, what about the W7 event viewer.

I can see the graphics card fault from about 2 months ago, but the only other error is a warning that the system took a long time to shut down… but no specifics.

Next, I replace the video card… but the slowdown is still there.

At one point, while trying to start the task manager, I get the following error:

Failure to display security and shutdown options…  The logon process was unable to display security and logon options when Ctrl + Alt + Delete was pressed.

Now thats a doozey! It must take a lot to stop task manager from starting!

A virus scan finds nothing wrong.

So I try updating the BIOS. Nope.

Ah! the jokers who setup the PC installed W7 with the hard drive in IDE mode.

I switch to AHCI mode, and everything looks fine for a while, but the slowdown soon re-appears.

I start clutching at straws, and disable wmpnetwk.exe (it seemed to be using a lot of CPU at one stage).

On a forum somewhere, I see a vague mention of replacing a faulty drive…

I figure: its worth a shot… even though the drive doesn’t give the typical signs of failure, many things are pointing that way.

So I clone the 500Gb WD5000AADS drive to a 250Gb Seagate.

The clone process works perfectly (many faulty drives are just not cloneable).

After installing the 250Gb drive, the slowness just disappears!

I am completely amazed that a drive can have such a “quiet” fault, that its almost impossible to test for it without first replacing the whole drive.

Vodafone RAS error 691

Computer Aid Posted on by

I setup a USB 3G wireless internet connection on a PC that was in a slightly rural area… ie they couldn’t get ADSL, and Optus mobile coverage was virtually nil.

The customer initially went with Telstra, but backed out when she found out the phone salesman lied about costs and features.

So she gets a Vodafone connection.

I setup the software, try out the modem, get onto google, do a search… it all seems to be working well.

Then the internet stops working.

The modem signal strength is 3/5 bars… so that should be a problem.

However, over the course of the next 45 minutes, I find the signal strength can vary from 1 bar to 3 bars…

Sometimes connecting to the internet works for a few minutes, other times I just get an error RAS 691

In the end, I can only conclude that either the signal strength is too variable to get a good internet connection, or there is a fault with the small USB modem.

An external modem with a more powerful antenna should make the connection a lot more reliable.

Thinkpoint Infection and 0x80072EFE error on update.

Computer Aid Posted on by

I’ve seen a few thinkpoint infections lately.

It seems to be very common, and looks scary, as it seems to take over the computer before its fully booted.

It also seems to bypass the likes of  AVG and Norton (no surprises there!)

However running malwarebytes quickly removes this annoying beast.

But in one case, the internet was still not working correctly.

That was fixed by clearing the windows filewall (control panel -> windows firewall -> advanced -> restore defaults

However, I then noticed that MSSE wouldn’t update correctly (and neither would Microsoft update).

I eventually had to remove the hosts file (c:windowssystem32driversetchosts) which was made more difficult due to it having its security attributes altered by thinkpoint.

All up, quite tricky.

I’ve noticed that some security software actually scans the hosts file, and will fix any alterations to it (while others will not touch it).

I’d say that in most non-corporate situations, the hosts file should always be left in its pristine condition… but in larger companies, you don’t want security software to change a customised hosts file… its a trade off, with no clear answer.

cryptorsamachine keys slows down backup.

Computer Aid Posted on by

I had setup a backup system (using an external USB drive) using the excellent syncback software.

However, I soon noticed that instead of backing up about 5 – 15 minutes to backup about 20 – 30 Gb, it was taking over an hour.

It didn’t take long to realise that the backup was spending a lot of time processing files in a folder with a name something like: cryptorasmachine keys

I found the culprit folder to be:

C:Documents and SettingsAll UsersApplication DataMicrosoftCryptorsamachine keys

It contained about 660 files, yet it took windows explorer about 2 minutes to display the contents of the folder, and display the number of files within it.

Of course it shouldn’t take that long to view 660 files… I’ve seen folders with 5,000 files that display faster than that!

I quickly find that they are relates to IIS (Microsoft web server software)…

Since the customer is using the XP home PC as an ordinary PC (no websites running from the PC, no domains), then there shouldn’t be many files in the “machine keys” folder.

After some careful research (and noting that most files are over 6 months old), I decide that the folder can be removed.

Of course, I play it safe, and rename the folder first, leave the computer for 2 weeks, then check that there have been no ill-effects, before fully deleting the machine keys folder (by then, a new machine keys folder had been created with just 3 files in it.

Once removed, the backup system runs quickly (as I would expect).

Outlook 0x800ccc78 error

Computer Aid Posted on by

This version of outlook has some unusual, and intermittent errors.

First, while sending emails, it would occasionally generate error 0x8004210B

That was easily fixed by just restarting the PC.

But then outlook would generate a more consistent 0x800ccc78 error.

I’d get this error regardless of the email size, and regardless of attachments.

The wisdom on the net said to check that the email address is correct, check your ISP etc.

I checked all those, but found nothing wrong (this account had been working fine for months previously).

I’m starting to suspect that the ISP has made some change.

The only thing that seems to make sense, is the outlook account options (the windows that has all the server settings … eg POP3 and SMTP settings).

I click on the “more settings” button.

Then under the “outgoing server” tab, I tick: SMTP requires authentication… and use same settings as my incoming mail server.

After that, sending emails caused no more problems.