My 32 bit windows vista has just had its second birthday and I’m beginning to have major problems with it. It has always run very smoothly because I have always been sure to keep it up to date with the latest updates and virus protections. And, despite what other people say about how "terrible" Vista is I really think its been much faster than any XP ive ever had.
I have Norton Antivirus 360 (version 1 i think) and there has never been a time without it and it says the computer is secure and it full system scans 2 times per week.
I also have Windows Defender and I click on it to full system scan it atleast once a month and it cant detect any viruses, but it likes to turn itself off without my permission and i have to turn it back on to scan (I heard that is because of Norton and is nothing to worry about, please correct me if im wrong)
I have a registry cleaner called Eusing Free Registry Cleaner and I scan the computer with it at least once per week and fix all of the registry issues, which seems to slightly speed up the computer for a couple of hours.
I also occasionally download and use the Microsoft Malicious Software Removal Tool and full system scan with it. It says while its scanning that 2 files are infected and when it is done scanning it says that nothing is infected and the computer is running normally, although its like it "forgot" that the computer has 2 infected files and doesn’t seemed to have done anything.
I also use the Disk Cleanup as commonly as the Microsoft Malicious Software Removal Tool and defragment once per week.
Now as far as memory goes I have most of the programs that came with Vista and a few others such as Photoshop Elements, Perfect Typing Pro (a typing program), Google Earth, & Mozilla Firefox (my main browser) and very few personal files. Most of my files, which are mostly thousands of pictures, are kept on 2 USB flash drives and aren’t kept plugged in most of the time.
The memory (RAM) is 2.00 GB and the computers rating is 3.0, according to the System page under System & Maintenance in the Control Panel.
In windows task manager the Physical Memory (MB) says
Total: 1917
Cached: 1209
Free: 39
Kernel Memory (MB) is
Total: 214
Paged: 140
Nonpaged: 74

I would really like to know whats wrong with this computer. Is it possible that I have an undetectable virus or that i got a virus from my flash drives (that i scan as often as the computer) or do i just need to dump the Cache or something?

I really don’t understand much of this stuff but, if anyone could give me (for example) the link to a safe program to either dump all of the unnecessary files, like temporary files, without getting rid of programs or important files or give me a link to a really good working virus scanner or something would be greatly appreciated.

Also be free to ask any other questions about memory, programs, downloads or anything else of the sort pertaining to my computer.