something's up wit my comp while im playing Half life these days, it keeps getting worse and worse. when i first got HL2, the gameplay was very smooth and my fps averaged around 60-70. Nowadays, no matter which server i play, things become more "shaky" and my fps goes down to like 20-30 (on good days) and 9-12 frames per second on bad days. It would get so bad that eventually my whole comp jst freezes and the game crashes. i'm not sure what the problem is and i tried lotta possible solutions but they all failed.
Here's my system info according to Steam:

Processor Information:
    Vendor:  GenuineIntel
    Speed: 3198 Mhz
    2 logical processors
    1 physical processors
    HyperThreading:  Supported
    RDTSC:  Supported
    CMOV:  Supported
    FCMOV:  Supported
    SSE:  Supported
    SSE2:  Supported
    3DNOW:  Unsupported
   
Network Information:
    Network Speed: 
    IP Address:  192.168.1.XXX
   
Windows Version:
    XP Service Pack 2 (Build 2600) (32 bit)
    NTFS:  Supported
   
Video Card:
    Driver:  Winvnc video hook driver
    DirectX Driver Name:  ati2dvag.dll
    Driver Version:  4.00.1636.1
    DirectX Driver Version:  6.14.10.6561
    Driver Date: 21 Nov 2002
    Desktop Color Depth Not Detected
    Monitor Refresh Rate Not Detected
    DirectX Card: RADEON 9550
    VendorID:  0x1002
    DeviceID:  0x4153
    Number of Monitors:  1
    Number of Video Cards:  1
    No SLI or Crossfire Detected
    Primary Display Resolution:  1024 x 768
    Desktop Resolution: 1024 x 768
    Primary Display Size: 12.60" x 9.45"  (15.75" diag)
                                            32.0cm x 24.0cm  (40.0cm diag)
    Primary Display Type Not Detected
    Primary Bus Type Not Detected
    Primary AGP GART Not Detected
    Primary VRAM: 294 MB
    Primary Monitor Vendor Not Detected
    Primary Monitor Model Not Detected
    Supported MSAA Modes:  2x 4x 6x     
   
Game Display Settings
    GoldSrc Game Resolution:  1024 x 768  (Fullscreen)
    GoldSrc Game Bit Depth:  16
    Half-Life 2 Resolution:  1024 x 768  (Fullscreen)
    Half-Life 2 MSAA Disabled
    HL2DM Resolution:  1024 x 768  (Fullscreen)
    HL2DM MSAA Disabled
    Counter-Strike: Source Resolution:  1024 x 768  (Fullscreen)
    Counter-Strike: Source MSAA Disabled
    Lost Coast Resolution:  800 x 600  (Fullscreen)
    Lost Coast MSAA Disabled

Sound card:
    Audio device: SB Audigy 2 ZS Audio [DE80]
   
Memory:
    RAM:  1022 Mb
   
Miscellaneous:
    UI Language:  English
    Media Type:  DVD
    Total Hard Disk Space Available:  152625 Mb
    Largest Free Hard Disk Block:  66265 Mb

I'm not sure if it's the video drive that i should update or if there's someting wrong wit RAM. i even tried shutting down most of my programs, but i still get this problem of slower and laggier performance. 
   

First of all did you read the "Tweaking Companion" I wrote a thread about?????
It will give you the knowledge you need to make fixes yourself and the satisfaction that comes with having found that particular fix :)
Anyhoo from what you posted your Video Card is not up to snuff....I remember a 9600 card I had and it just wasn't able to keep up with the demands of this game (HL2)......
As was mentioned earlier try lowering your res. to 800x600.....you should be in VIDEO options where these adjustments are made so while your there put EVERYTHING on LOW...TRUST ME ON THIS!!!!!! The picture of the character you will use will look REAL blurry BUT in game it wont be......
REMEMBER...when you game on-line you want real good FPS.......who cares if it doesn't look pretty it's about Frame Rates, Rune, FRAMERATES!  and framerate is KING! Unless you have a higher end Video card so you can play at higher res and all the pretty stuff on then your gonna have to suffer till you get a better card.....
Now this is a quick fix....DEFRAG YOUR HARD DRIVE...it may take a long time but it's worth it....defraging will make sure everything is where it's suppose to be...so the game won't studder and freeze alot on you ....think of being at home and wanting something to drink...would you so in your bedroom looking for it ? Of course not it should be in the Kitchen right?But even the PC knows it goes in the Kitchen but WHERE in the kitchen?? Defragging will put it where it suppose to be ..in the Fridge!
If theres one more thing I'd like to add is color is set to 16bits where it should be at 32...these will make it easy on your eyes and keep you from getting Headaches!! The monitor is Flashing very fast and your eyes may not tell the difference but your brain can and after a lil bit your gonna get headaches ..32bit color will fix that and make your game look better...let us know how it went. :)

OR you can borrow shiggies giant magnet... 

I'm impressed with your great patience RUNE...  "That There" list is like a GAL novel and shows me how much and how little I know...

But alas... I've been having similar problems. Tomb flutters, death shakes, freezes and crashes on my machine... in addition to the ongoing server crashes... been going on for a couple of weeks.

Maybe I should take up listening to audio books,

 

Medkit!