Ram eating monster of freezing

Hallo,
I have a small problem with my lovely PC. When I turn it on it takes ages to load up into the logging screen, but that's no the problem. The problem is that since two weeks or so I have noticed a significant decrease in the "speed" of my work station. When I'm browsing system folders in windows explorer, or the internet in Opera everything is slow. Sometimes Opera and win explorer are freezing in "not responding" state and I have to wait a while, or it is just so sluggish that it is not possible to use it, changing tabs takes about 20 seconds since clicking on them. One thing I noticed that the ram usage is spiking and the CPU usage is knida... low on the pic i will give it is 25% but sometimes ram is 94% and CPU is 4 % so I would say it's interesting ...

I believe you can turn on your task manager and see what is what since mine is in polish ...

Ok so these are the specs:
Name: Hp pavilion m9460pl elite
CPU: intel core 2 quad q9400
RAM: 4 Gb
HDD: 1,5 Tb
GPU: ATI radeon HD 4850


I am a bit acquainted with computers on terms user-pc, so I have tried cleaning registry, defragmentation, cleaned the startup ( but maybe I left too much stuff in there...).

So please help me : ]

Welcome
Can be several causes
Update and make a full scan with your anti virus
Download, update and make a full scan with malwarebytes

If they are negative test memory
http://www.geekstogo.com/forum/topic/246994-guide-to-using-memtest86/
Run for 8 passes and then test each stick in a good slot for 6 passes

If you pass that
Give us a screen shot of task manager (show process from all sources).
Use only Ccleaner to clean the registry.

Do you have a lot of available space on your hard drive.?

Thanks for responding quickly, and sorry I tried to post the topic in games I just didn't notice this :X. I'm doing the antivir scan right now.
I cleaned with Ccleaner only, and i have 149Gb of free space from 686Gb ( C) on the windows HD and 444 Gb free from another 686 Gb ( E) and i have a partition called "D" but its 12Gb reserved for recovery image.

Do the other tests and if you get nothing give me the screen shot as requested.

I did the anti virus scan and ant malware scan but it gave no results. Tomorrow I will do the memtest and send in the results :]

I am very sorry I did not keep my word...
I have noticed something interesting in the task manager ...
All of those appeared when I clicked show processes for all users

You must understand, does not seem to be in English, I have no idea what it is.

It looks like it could be a bad plugin for Oprea. 500Meg for a browser is huge.

Have you tried using IE for a while and see if you get the slow downs?

Windows will routinely use half of your RAM because you have it.

If your scans come back clean, I think you might want to try a systemm restore to before you had problems, as it may have been an update that installed wrong.