Computer acting funny after crash

Running a 2.4 gig Core2 Duo system, XP Pro, 2 gigs ram..

Had an issue where I got a BSOD a couple of times in a row in a short
period, just kind of out of nowhere. One time was playing a YouTube
video, once while doing something with an audio recording app.

On a hunch I pulled and reseated the RAM sticks, so far haven't seen a
revisit of the problem.

Some of observations about the crash - it borked the active desktop -
got a white background and a blue triangle with a "Restore Active
Desktop?" radio button. I've seen this before after crashes, but this
time clicking it didn't seem to have any effect. It goes to my normal
desktop now after a few reboots, but I notice that when booting, the
system takes a lot longer and also hangs for a moment at this point
where the background desktop image disappears for a bit, there's a
blue background, the desktop icons are in incomplete form. Don't
recall that it did this before.

When it finally does go back to a background image with icons, it
takes longer to boot and be ready for action. In fact everything is
sluggish. Apps are taking longer to load, takes forever for Firefox to
come up. The task manager showing levels of CPU use 15 - 50% - on a
Core2 Duo system - where I get the sense it shouldn't be laboring that
hard, not much going on. The machine just "feels" different in its
behavior than pre crashes. Seems to remain this way after several
reboots.

Ran a Virus Scan with freshly updated Bitdefender, found one cookie it
got rid of, nothing sinister.

Any suggestions as to what might be going on?