When ever I run RTC: Wolfenstein, I get Low Desktop Color Depth "It is highly unlikely that a correct WINDOWED dispay can be intialized with the current desktop display depth. Select 'OK' to try anyway. Press 'Cancel' if you have a 3Dfx Voodoo, Voodoo-2, or Voodoo Rush 3D accelerator installed, or if otherwise wish to quit." Then I press 'OK' and i get this from the Wolf Console:

Wolf 1.1 win-x86 Dec 17 2001
----- FS_Startup -----
Current search path:
C:\PROGRA~1\RETURN~1/main

----------------------
0 files in pk3 files

Running in restricted demo mode.

----- FS_Startup -----
Current search path:
C:\PROGRA~1\RETURN~1\demomain\pak0.pk3 (1846 files)
C:\PROGRA~1\RETURN~1/demomain

----------------------
1846 files in pk3 files
execing default.cfg
couldn't exec language.cfg
couldn't exec wolfconfig_mp.cfg
execing autoexec.cfg
Hunk_Clear: reset the hunk ok
...detecting CPU, found Intel Pentium III
Bypassing CD checks
----- Client Initialization -----
----- INITIALIZING Renderer ----
-------------------------------
Loaded 714 translation strings from scripts/translation.cfg
----- Client Initialization Complete -----
----- R_Init -----
Initializing OpenGL subsystem
...initializing QGL
...calling LoadLibrary( 'C:\WINDOWS\system32\opengl32.DLL' ): succeeded
...setting mode 3: 640 480 FS
...using desktop display depth of 24
...calling CDS: ok
...registered window class
...created [emailprotected],0 (640x480)
Initializing OpenGL driver
...getting DC: succeeded
...GLW_ChoosePFD( 24, 24, 0 )
...35 PFDs found
...GLW_ChoosePFD failed
...GLW_ChoosePFD( 24, 24, 0 )
...35 PFDs found
...GLW_ChoosePFD failed
...failed to find an appropriate PIXELFORMAT
...restoring display settings
...WARNING: could not set the given mode (3)
...setting mode 3: 640 480 FS
...using colorsbits of 16
...calling CDS: ok
...created [emailprotected],0 (640x480)
Initializing OpenGL driver
...getting DC: succeeded
...GLW_ChoosePFD( 16, 16, 0 )
...35 PFDs found
...GLW_ChoosePFD failed
...GLW_ChoosePFD( 16, 16, 0 )
...35 PFDs found
...GLW_ChoosePFD failed
...failed to find an appropriate PIXELFORMAT
...restoring display settings
...WARNING: could not set the given mode (3)
...shutting down QGL
...unloading OpenGL DLL
...assuming '3dfxvgl' is a standalone driver
...initializing QGL
...WARNING: missing Glide installation, assuming no 3Dfx available
...shutting down QGL
----- CL_Shutdown -----
RE_Shutdown( 1 )
-----------------------
GLW_StartOpenGL() - could not load OpenGL subsystem

My PC is a Dell OptiPlex GX100 and it runs the latest Windows XP. My graphics cardis and Intel 82810-DC100 Graphics Controller.

Can you GUYS help me fix this PROBLEM or should I upgrade my video card? If you can't afford an updated video card or don't plan on playing many games I'd suggest getting the latest drivers for this chipset at the below link.

http://downloadcenter.intel.com/Product_Filter.aspx?ProductID=798

Otherwise I'd strongly suggest getting some type of improved video card for your computer.When I tried installing the update, it said I already had a newer version of the update. So I've decided to upgrade my graphics card, but I don't exactly know what type of graphics card to buy. Because I don't know what kind of graphics card this "Intel 82810-DC100 Graphics Controller" is (is it even a video card or is it attached to the motherboard?). For this PC should i buy an AGP or PCI video card? "Intel 82810-DC100 Graphics Controller" is an on-board video chip.
You'll want to get AGP video card, which is faster, then PCI.
You have to check, though, if you have AGP slot on your motherboard.
Get a card with 512MB RAM, which will cost you around $100.