Why is my computer slow for a while after I start it up?

Anti-malware Scans

The single most common reason for exceptionally poor performance for "a while" after turning your computer on is an anti-malware scan.

Most anti-malware programs (both anti-virus and anti-spyware) operate at two levels by default: so-called "continuous" protection, which attempts to monitor activity in real time as you use your computer, and periodic scans, which quite literally scan your computer's entire hard disk for malware.

By default, periodic scans typically happen once a day - the question is when.

If you leave your computer on 24-hours a day, chances are that the scans will happen in the middle of the night when you don't notice or care. However, if your computer is turned off overnight, the anti-malware scans that were missed overnight may begin immediately after you login.

And your system slows to a crawl.

There are several possible solutions: switch to a less intrusive anti-malware scanner, or configure your anti-malware tools to be less intrusive when they scan, if that's an option. Many tools need not impact your computer's operation so severely while they scan.

Another option might be to configure the scans to happen at a time when your computer would be on, but not as actively used - perhaps during lunch or dinner time.

Or you could leave your machine on all the time.

Backups

Backups are probably the second most common cause of prolonged performance issues after startup.

Backup software often operates much like anti-malware software in terms of scheduling. Most commonly, backups will be scheduled for once a day. If the computer is off at the time of the scheduled backup, then the backup program may very well start the backup as soon as the machine is turned back on.

The solutions here are similar: lower the priority of the backup, if you can to be less intrusive, change the scheduled time of the backup to have a higher chance of success, or leave the machine on.

And if it turns out that backups are the issue here ... well good on you for backing up. Regardless of when or how they happen, it's critically important that they do.

Content Indexer

This falls into the category of "maybe", but it's worth looking into.

The content indexing service periodically scans your hard disk like anti-malware and backup tools do. As a result, it makes sense that it could impact your start-up performance, too.

The quick test here is to simply stop indexing your hard disks. Right-click on each in Windows Explorer, click on Properties, and on the General tab, uncheck the option to allow indexing.

Other Services

Naturally, anything that's present in your system's auto-start list is suspect. Grab a copy of autoruns, a free utility from Microsoft that will let you examine what starts automatically when you start login to your machine.

Another approach is rather than guessing, which to be honest is all we've done so far, is to run a tool like Process Monitor and analyze what's happening while your machine's being so slow.

Armed with the results of that analysis, you should then be able to make some decisions and chances to improve your start-up experience.

I Was Serious About The Coffee

It's not at all uncommon for your computer to "take a little while" when you first start it. You may be able to use it pretty quickly, but depending on how it's configured, you may see other activity continuing for some time as start-up tasks run and eventually complete in the background.

That's one of the reasons I do, indeed, login to my computer and then go get my cup of coffee. I could start using it right away, but it's just the most responsive if I give it a chance to complete its own morning ritual.

But even if I skip the coffee, the computer's usable. I'm also only talking a minute or two, and definitely not half an hour. That's a situation where I'd definitely be looking at the things that I've outlined here.