slow system hdd performance after a unexpected shutdown

This is something I have seen occur multiple times in 17 years of using windows, after a unexpected shutdown windows i/o performance slows right down and I still dont have the answer to it.

Today I accidently cut the power to my pc, so windows didnt crash it just lost power.

Windows took about twice as long to boot.
After it had booted the system hdd was very busy doing I dont know why (wasnt superfetch or virus scanning). The i/o was used by the system process.
Outlook took a looooong time to open. it then also took a very long time to close deleting the deleted emails which are usually way faster.
Internet explorer took about 2 minutes to restore crashed tabs which was massive disk i/o.
Opening tiny apps where the hdd light either flashes very briefly or doesnt come on at all have a noticeable 1-2 sec delay with the light on solid.

I expect after a manual defrag things will be back to normal.

Dos all the prefetch data get trashed on a unexpected shutdown or something?

In Process Explorer, when you dbl-click the System process as it's generating heavy I/O, can you state the start address of the highest-running thread? You won't be able to access the thread's stack, but the start address might be enough to determine what's going on.

Otherwise, if you do not see System running much but instead see heavy activity on Interrupts then you know that an interrupt storm is occurring, which means a device is flooding your system with continual interrupts or a repeated interrupt that is constantly attempting service.

I would also recommend Disk Check with both boxes checked for HDDs and with Automatically fix file system errors checked for SSDs. NTFS fixes file system errors and allocates around bad sectors on the fly most of the time, but when it fails, Windows will start to suffer and you may find in your Event Viewer logs that you are being asked to run a disk check. Most people do not check the Event Viewer logs and are not aware of this behavior. This can result in the high I/O problems you are having.