Dell Vostro 1710 lags on old games

Hi all,
Im new here so i'll try to keep my question clean.

Recently I bought a new laptop for gaming and music recording, and so far it hasnt dissapointed me, untill I installed some old games like command & conquer 95, Red alert 2, and cossacks: back to war. They all seemed to run fast, but after 5 seconds the game starts to lag, and it becomes unbearable when I start building my army. Anyone knows how? On the forum I found this guy with the same problem but no answer worked for me. Here is my little description.

Problem
-LAG at singleplayer, LAN play AND internet
-It's not my network and not my graphic card, everything is capable to run

My opinion:
Probably something with system compatibility or 2 processors, but on other notebooks with 2 cpu's it worked fine, so there is still my graphics card that can cause the problem.. maybe my notebooks is too good to run old games? Can i disable some system props to let it run just fine?

System props: (Dell vostro 1710)
-Intel dual core 2.5 ghz T9300 6MB l2-cashe, 800mhz fsb
-Windows vista bussiness DOWNGRADED TO XP PROFESSIONAL
-3GB DDR2 RAM
-320GB 5200RPM SATA hard disk
-Nvidia GForce8600M GS 256MB
-Realtek Gigabit network card (I use cable)

What I tried:
-Closing all network connections except ethernet cable
-Using Wireless
-Disabling directdraw 3d acceleration at dxdiag
-trying different monitors and screen resolutions
-windows 98 & 95 compatibility mode with all possible options (limited resolutions etc)
-changing to 1 cpu instead of 2
-changing task priority

 

I have no idea but props to you playing the old red alerts....great f*cking games!