You've got a "virus" problem.
BlackDove wrote:Those are all useless or worse than useless and detrimental. AVG secure search is malware. Ccleaner can screw up your registry too.
I second this. AVG is horrible, and I've had CCleaner mess up my registry. Use
Avast Antivirus instead. It's free and better than Microsoft Security Essentials IMO. I only use Avast on my computers (no other anti-malware stuff) and have never had a problem with slowdowns. Uninstall AVG before you install a different anti-virus program. It's bad to have 2 anti-virus programs running. I'd also argue that it's detrimental to performance and pointless to have active malware programs running alongside modern anti-virus software. It's just more proecesses' that are doing the same task, sucking up resources.
If you use Avast, do the "custom installation" option and uncheck all the grime fighter, VMSecure, etc etc (stuff that doesn't look like core-AntiVirus functions) they're just bloat that most users will never use anyway. "Grime Fighter" will actually give you a pop-up after a while, but is only available on the paid version. It's their way to upsell.
Are you actually RUNNING virus SCANS, or just assuming that "active protection" of AVG is getting the job done. You need to actually run virus scans from time to time to remove bad stuff (AVG sucks at removing bad stuff even with scans...so). Note: Avast doesn't schedule scans by default upon installation. You need to set up a scan schedule.
When's the last time you cleaned your browser history and cookies? Defragmented the hard drive? These are simple (albeit manual) tasks that can be done in your browser and/or Vista.
As others have said, more RAM will improve the performance of your PC, but RAM itself is NOT the cause of a gradual slowdown. It's possible/obvious that you've got background processes' that are sucking up tons of resources, likely that along with the CPU and hdd activity, it's stealing RAM also. This all leaves less resources to run programs that you're actually using. Given that you said 1.5GB and Vista, I'd assume you've got DDR2 RAM which you should be able to get an additional 2GB for $10-15. Do that regardless, these days it's recommended to have at least 3-4GB of RAM. What is the brand/model of the computer? Do you have 32-bit Vista or 64-bit? Are there empty RAM slots that you could fill?
How many tabs do you typically have open at a time in Chrome?
Already mentioned, but going forward: Make sure you're reading each page of software installations. It is VERY common for free software to come bundled with random other unrelated programs/toolbars in various degrees of sneakyness. Always select "custom installation" when given the option. Unselect all programs/toolbars that are not the one you're currently installing. If you wanted the other bundled programs/toolbars you can easily download them separately. This is the most common pitfall for the vast majority of users: just clicking next-next-next until a program is installed without paying attention to what else is coming along for the ride.
Main: i5-3570K, ASRock Z77 Pro4-M, MSI RX480 8G, 500GB Crucial BX100, 2 TB Samsung EcoGreen F4, 16GB 1600MHz G.Skill @1.25V, EVGA 550-G2, Silverstone PS07B
HTPC: A8-5600K, MSI FM2-A75IA-E53, 4TB Seagate SSHD, 8GB 1866MHz G.Skill, Crosley D-25 Case Mod