PC only "wants to start" at 2nd try - 7 x64

[diogocv]

Folks, I'm having a really weird problem with my news 7 x64 system. First of all, I was using Vista Home Premium x64 until yesterday, and this problem started with Vista. last night I upgraded my pc with a new pair of hd's (Seagate barracuda 7200.12 500gb) and set them in raid 0. They replaced my old samsung 250gb hd.

Ok, so this is what's happening: I start my pc, the screen stays black for about 10 seconds. Afther that it starts normaly with the post screen of my Gigabyte motherboard, procced to the raid chipset checkings, then to the "loading windows" screen. But after that the screen just stays black, no "welcome / user login" screen appears.

Then, if I press the restart buttton it all starts and I can log in and use windows normally.

Does anyone have a clue on what this might be? It's really annoying, since I have to restart the pc every time I want to use it (and it might damage something, right?).

My system right now is: C2D 6750 (stock speeds), Gigabyte P35C-DS3R, 4x1gb Corsair XMS2 PC 6400 (stock speeds), Zalman 460b-aps PSU, 2 Seagate Barracuda 7200.12 500gb in raid 0, ATI Hd 4850.

Thanks in advance!

PS: Sorry for any english mistakes

PS 2: this problem was already happening with Vista and the old HD. So i guess it's not a hard drive related issue.

 

[The_Prophecy]

Try downloading Memtest86+ and running a RAM test. Let it do a complete pass first (yes it will take awhile to complete).

 

[diogocv]

Try downloading Memtest86+ and running a RAM test. Let it do a complete pass first (yes it will take awhile to complete).

I'll do this tonight - as it takes such a long time like you said. I'll post the results tomorrow. Thks for the reply