Lag issue while playing WoW on my new computer

[Cervios]

Hello !

I bought me a new computer lately ( 4 days ago ) and first of all i thought it was atleast a good upgrade compared to my previous computer - to play WoW on.
My last computer spec's are:
Intel Pentium 4 3.2Ghz
2gb DDR (think it's 500 mhz)
Ati HD 4650 (1gb) with HDMI port
Full HD monitor aswell.
160g WD IDE (for OS) 500gb WD Sata(for additional space, games etc..)
the OS was Windows XP Professional 32 bit. (with latest windows updates installed, also all drivers up to date)

Now to my new computer spec's (The computer it self is Acer Aspire x1930) :
Intel G530 (Celeron 2.40Ghz Dual-Core) 64 bit
4gb DDR3 ram
500gb WD
XFX ATI Radeon HD 5450 (1gb) with HDMI port
The same Full HD monitor still. (Philips 244E)
The OS is, Windows 7 Home Premium 64 bit

Now the the problem i found as son as i started WoW for the verry first time. Once i logged in to my character i saw some kind of lag, not any lag that i've seen before. I run WoW with 35-45 FPS without any real drain, even inside any major city's ( many other people, and alot of stuff is moving around ).
When im about to move any direction, it feels like it takes "time" to think of what i tell it to do. And while i move, my character is like jumping now and then forwards or backwards ( one step or so ).
Have to admit that i have looked around within my computer about drivers to try sort out this with the knowledge i got of computer issues. But this i cannot fix myself it seems.
I downloaded the graphic card driver from Microsoft's website, the one that is for my Graphic card. And i have DirectX 11 aswell.
But still i have a feeling that the drivers or anything about the screen is wrong.
But it could be anything else, so if anyone of you can help me out i would appreciate that.

Best regards Cervios

[Runzlikegirl]

Check your graphics settings and make sure you have DX11 enabled.

If you put the settings on full low does it go away?

Is the card a PCI or PCI Express card? (graphics)

[Cervios]

Check your graphics settings and make sure you have DX11 enabled.

If you put the settings on full low does it go away?

Is the card a PCI or PCI Express card? (graphics)

Which settings? And were do i see if the DirectX is fully installed? or enabled.
The graphic card is PCI Express x16.
Thanks for fast answear btw !

---------- Post added 2012-10-03 at 07:16 PM ----------

I have tested all the graphic settings in WoW - from Low to Ultra. And only ultra and the second last one is starting to make more lag ( in a different way )

[Runzlikegirl]

Which settings? And were do i see if the DirectX is fully installed? or enabled.
The graphic card is PCI Express x16.
Thanks for fast answear btw !

---------- Post added 2012-10-03 at 07:16 PM ----------

I have tested all the graphic settings in WoW - from Low to Ultra. And only ultra and the second last one is starting to make more lag ( in a different way )

Under graphics-advanced look and see what API your running.

---------- Post added 2012-10-03 at 06:08 PM ----------

Also,
Follow these instructions
http://www.guru3d.com/content_page/g...r_sweeper.html

Then install the newest driver for your card from the ATi website, Microsoft is normally way behind.

[Cervios]

Under graphics-advanced look and see what API your running.

---------- Post added 2012-10-03 at 06:08 PM ----------

Also,
Follow these instructions

Then install the newest driver for your card from the ATi website, Microsoft is normally way behind.

Ah allright - so with that program i can remove all my graphic drivers and make it install the latest driver for my card?

Here is the information of my graphic card:
AMD Radeon Graphics Processor (0x68F9)
Internal DAC(400MHz)
ATI Radeon HD 5450
Bios information 113-545XZCH-00
Total graphic card memory avible: 2807mb
Dedicated Graphic card memory: 1024mb

Thanks alot for your help, this might be the sulution to fix this ! Really appreciate it