Foo - Software that analyzes system resource use?

My 1.5yr old Acer laptop seems to be slowing down as of late. Now it sometimes stutters while playing music and doing something online, such as farmville. Similarly, movies even have the occasional lag. I've looked inside task manager, but I don't see many programs running that would be such a hog. Is there some software I can download that will tell me where my processing power is going?

I've run ad-aware and Spybot and both came up clean.

This laptop has Windows Vista.

You can use the Task Manager for basic analysis or use Resource Monitor (Windows Vista and above only) for more detailed perusing. ResMon gives you a very thorough breakdown on memory, disk, CPU and network utilization right down to the API level.

Keep in mind that with most Windows installation, performance tends to inherently degrade over time. This is usually due to resource growth from third-party applications, registry growth and lingering "stuff" from uninstalled programs and services. Have you installed any new software? Have you cleaned your registry? How many background services are you running? All of these things (and more) contribute to performance issues.

Going out on limb here, as I'm not an IT/CS person. Farmville is an online game, right? The movies, are they streamed or are they from a disk? Any issues when working off-line? I ask because I also have an Acer laptop (3GB RAM, Core2Duo 2.0 Ghz) running Vista Home Premium 32-bit. I was having trouble with streaming video big time, audio occassionally, and sometimes web pages would not load at all. Those issues went away once I switched over to a different ISP that had more bandwidth (and installing a new router). Might just be your network connection.

Is the harddisk activity light blinking when you experience the slowdowns? Something is probably hitting the disk very hard, possibly anti-virus scanner or some search indexing process, and it won't show in Task Manager, as it's not CPU or RAM-related.

It's really difficult to diagnose, though, unless you can find the culprit straight away. Maybe it's time for a re-install?

I've installed a lot of new software, unfortunately. I'd like to start purging the system and simplify again. Like you said, though, stuff always "lingers." I'll clean my registry ASAP -- thanks.

I have 58 services running, and as I am playing music now, my CPU usage is hovering around 25%. Deactivating Dolby Headphone reduces CPU use by an average of 4%. This laptop doesn't have a dedicated sound and video card like my desktop does, so I'll admit I may have come to expect higher performance, but it definitely shouldn't struggle to play music and farmville at the same time.

The two posters above my response submitted while I was typing.
No1mad, the media I play is all loaded on my hard drive. I've definitely experienced no connection issues with my ISP.

Tero, the harddrive light seems to continuously blink quickly. I'd like to do a re-install, but this laptop came shipped with Vista preinstalled and no restore CD.

Um, you didn't take the time to create your own back-up discs?