Bossi's Counter-Strike Help Links

The infamous FPS Drop in Counter-Strike

The answer to the infamous FPS Drop in Counter-Strike is: I have no idea!

Seriously, if you read through the CS forums (not only at coL but all over the web) do numerous People have this problem with the random FPS drop.
Until now is there no answer to fix the problem for all. Things that may help and are worth a try are:

Update your Drivers - Graphic Card, Chipset, Sound
Do this properly by de-install the old driver first, reboot and after the reboot install the new set of drivers - remember to reboot again before you test if this helped somehow (Important: If you made the FPS guide, redo it, because with a different driver comes a different OpenGL file!)
Run intensive Scans for Virus/Trojans/Worms and for Spyware. Do a full scan and not only 3 minutes and abort it, because it seem to take ages.
Read (and follow) the Computer Maintenance Guide
Make sure that not needed Applications don't run in the Background
Heat can be a Problem. Make sure your Vid Card and your CPU are not overheating (don't ask me how to know.. if you had read the Maintenance Guide then you would know how to know ^^) - Short Term Solution: open the computer case so that hot air can ooze out.
A weak PSU (Power Supply Unit) can be the reason. Especially if you upgraded your PC with more RAM, better Graphic Card or a powerful CPU.
Try out different Netsettings. The popular 101/101/25000 are not always good. Those are LAN settings and nothing for laggy online play and/or modem user.
Reboot your Computer - simple but effective. Reboot your computer now and then to free resources that may be in use by other Applications you used before.
If this all fails, try reinstalling Steam and Counter-Strike and test it with Default Configs and Settings
to be continued...

Give the things above a try and see if it help. If not, do not blame me!
Note: Smokes are FPS killers! If you have a weak vid card and there are Smokes on your screen, your FPS will drop and there is nothing you can do to prevent this (except to upgrade your pc). Just ignore the smoke and the FPS drop, run through the smoke and deal a round free Headshots (if you HS a teamm8 by accident [or because you suck], immediately curse and blame the FPS drop and they will forgive you ^^)