Random Hangings and Problems at Startup

Hi.

I have a Pentium CPU running at 2.50GHz, 2GB of RAM, a Nvidia Geforce 9600 GT and W7 Ultimate 32-bit.

Since last week, i've been having some big issues during the startup.
The computer will boot just fine, but when the desktop appears, it slows down a lot, with the computer making a very characteristic sequence of sounds. However, CPU usage never goes over 60% and memory usage never goes over 50%.

But the weird thing is, is that most of the times, the computer will eventually speed up, but then, im not able to open anything. I mean anything. No programs, no applications, nothing from Windows Explorer, nothing.
If i'm quick enough, i can manage to open something, but then it will stop working or, in the case of Google Chrome, not being able to access another website, apart from the one in which im already in.

But sometimes, like yesterday, it will boot fine and run trouble free throughout the day.

I've done System Restores, memory checks, registry cleanups, defrags, antivirus checks, removed programs from the computer and the startup, ran startup repair and i run CCleaner regularly (it actually seems to be the best short term cure for it), and no problem went away unfixed.

Any help? What staggers me is that this happened all of a sudden, and it's getting quite frustrating.

Remove current antivirus in safe mode with the tool here:

AV Uninstallers - Windows 7 Forums

Replace with MSE after rebooting.

Can i ask what difference will it make?

Why would I have posted what I did, based on your original post?

You asked for help. I provided it.

Im doing it, but it's an innocent question. I just wanna know why am i doing this.

To attempt to fix the issue, of course. It's the first thing needing to be done and has excellent chances.

I'm sure you currently have Norton or AVG, but even if not, still do so.

I had Avast. I rebooted the computer and now MSE is stuck looking for virus and spyware definitions.

Cool. Let us know how it goes on and if things go well after some time.

No. I meant that MSE got stuck because of the compters problems, because nothing would open. And it wont work in Safe Mode.

Hopefully you removed Avast with the tool I linked to.

You're also welcome to type msinfo32 in the start menu then press enter. File | save on the opened screen. Zip the saved file and attach it to a post.