Windows 7 Enters Restart Loop: Error c000021a among others

[AH1]

Hello, let me start by saying thank you for any help you can provide. My level of tech knowledge is pretty high, and yet I am stumped by this issue. I know this community is a source of high quality reliable knowledge, which is why I turned here both in the past and now.

So, here is what is happening. My computer suddenly restarted on me this morning and when it tried to boot, I receive the dreaded blue screen of death with the most reoccuring error being c000021a. However, this is not the end of the problem.

Sometimes it won't let me enter into safe mode, or even run the repair diagnostics. Other times it will. Sometimes it will almost load safe mode et al. but then end up on a perpetual black screen with nothing happening. Other times the monitor will simply wig out and flash a ton of bright colors at me.

It goes without saying, but I have attempted a system restore to no avail several times. I have uninstalled recently installed programs whilst in safe mode, and I have run ever repair diagnostic I can think of. Nothing seems to be fixing this issue.

Obviously, the next step I can think of is to do a system wipe and reinstall everything, OS and all, but that does not strike me as a great option, and I'd like to avoid that if possible.

Please, don't assume I've done anything right or wrong, and just give me the best advice you can. I'm willing to try anything possible. Any help is appreciated. Thanks!

[Bob_180_Bob]

Hi,
Please look at this site to see if you have options you have not tried.

http://www.sevenforums.com/tutorials/681-startup-repair.html

[AH1]

Thanks Bob, I tried most of that already.

But I think I figured it out. I think my PSU is starting to grow senile in its old age (it's over three years old now!) and my graphics card is putting too much strain on it. I'm probably going to have to upgrade to fix the problem. If I let it cool down for a bit first, the computer boots no problem.

Maybe that's a coincidence?

[stryker4526]

Thanks Bob, I tried most of that already.

But I think I figured it out. I think my PSU is starting to grow senile in its old age (it's over three years old now!) and my graphics card is putting too much strain on it. I'm probably going to have to upgrade to fix the problem. If I let it cool down for a bit first, the computer boots no problem.

Maybe that's a coincidence?

That might be it. Computers can do some pretty strange stuff when they're not getting enough power. Have you looked up the error code you've been getting?

[AH1]

Yes, the error code I listed in the first post is a STOP error when a fatal system crash happens due to a third party application doing something. But what it really means is, in not so many words, "Important program/driver/function can't load, sorry bud".

Anyway, when that system failure happens, the computer restarts to save important data and protect the system. However, if it is overheated or not enough power is reaching the critical systems in order to boot up, it'll just keep restarted after the system memory dump.

So, I deduced logically that there must be something interrupting the process to cause this to happen. Whether or not that's the PSU, I don't know for sure. What I do know is that after resting, the computer runs like a champ again.

[assis1313]

Hello, let me start by saying thank you for any help you can provide. My level of tech knowledge is pretty high, and yet I am stumped by this issue. I know this community is a source of high quality reliable knowledge, which is why I turned here both in the past and now.

So, here is what is happening. My computer suddenly restarted on me this morning and when it tried to boot, I receive the dreaded blue screen of death with the most reoccuring error being c000021a. However, this is not the end of the problem.

Sometimes it won't let me enter into safe mode, or even run the repair diagnostics. Other times it will. Sometimes it will almost load safe mode et al. but then end up on a perpetual black screen with nothing happening. Other times the monitor will simply wig out and flash a ton of bright colors at me.

It goes without saying, but I have attempted a system restore to no avail several times. I have uninstalled recently installed programs whilst in safe mode, and I have run ever repair diagnostic I can think of. Nothing seems to be fixing this issue.

Obviously, the next step I can think of is to do a system wipe and reinstall everything, OS and all, but that does not strike me as a great option, and I'd like to avoid that if possible.

Please, don't assume I've done anything right or wrong, and just give me the best advice you can. I'm willing to try anything possible. Any help is appreciated. Thanks!

Hello mate reformate your drive and then see if its still happening...

[Windows7Guy]

Hello AH1,
It seems like there is a hardware problem.... you may need to reload Windows if registry is corrupted.

Have you checked compatibility?
Just an FYI for you.

It is always best to check with the software manufacturer FIRST. They will tell you if they have tested the product and the version, as well as whether or not it will work with Windows 7.
Check out the Windows 7 Compatibility site: (There you will find out about hardware and software compatibility.)
http://www.microsoft.com/windows/compatibility/en-us/default.aspx
There is a pulldown from which you can choose "hardware" and "software".

There are also some great articles, instructional videos and such to help with your Windows 7 at our Springboard site:
http://technet.microsoft.com/en-us/windows/default.aspx

In any event a lot of the times, Vista drivers will work in lieu of Windows 7 drivers, however, it's not 100%!

As stated previously, it's best to have the Windows 7 certified drivers installed.

Thanks again,
John M.
Microsoft Windows Client Support

[Technocrate25]

There are several causes the stop c000021a error might appear on your system. Here are some of the most common reasons:
* The failed service pack installation
* The incompatible system service or device driver
* An incompatible third party application
* Some mismatched system files
* A back up program on the hard disks that has failed to restore some files
There are several things you can do in order to resolve this type of problem. In the case you have just installed a service pack, third party application or device driver, you need to try to disable or uninstall it. In the situation the problem still persists, it would be recommended to start your system by making use of the Windows advanced option of the Last Known Good Configuration.If you are still getting the stop c000021a error, you will perhaps need to reformat your hard disk and restore all the data by using the data you have recently backed up.
A registry cleaner software might be a good solution for you to solve the stop c000021a error, since this type of software will check all the registry entries from your system, will remove the unnecessary or damaged entries and you will have good chances to get rid of the annoying stop c000021a error