I have the same problem sometimes.
Normaly I have 20-60 ping. But in last 2 months I have more then 150ping.
Just to clear something out first. The high ping is around 90+. At 90 you can still play the game, but you will not kill as many enemies as you would with 60ping. Now, with 150+ ping you cant even play. Because as soon as you click fire button on your mouse the game jams for you, and you get killed.
My friend once told me "maybe you have spyware/adwere or some shit like that". So I instal CClean, SpyTerminator and lot others. But they never find anything. So I was thinking, even tho I have NOD32(antivirus), which is active all the time, maybe some virus is in my PC(like spyware), that NOD didnt detect, and now no other program can't detect it when its in. So I get connected on one server and then hit CTRL+ALT+DEL once to enter in Windows Task Manager. And I enter in Processes part to see if some program is using my RAM memory when I play the game. And I see that my explorer.exe file is using 70% of it.
I fix this problem by formating my C hard drive and reinstaling windows again on it.
Then I install CS again, and I have 20-40ping. It works every time.
The only problem with this, is that I need to reinstal all the drivers and all the programs I need. And it last few hours.
