blank screen after windows boot HELP

not a while a go i got a new pc system. NF520-A2 SE with 2GB ram, HITACHI HDP725032GLA360,nvidia 9500gt manli, optiarc DVD RW AD-7200S and a AMD athlon 62 X2
i got it with instaled windows,and sometimes when i turn on/restart
the system loads to the wndows logo..and continues to load...forever,or LOAD and then the screen goes blank black....forever...
sometimes its loading loop,i restart,then blank load,then when it loads,the system block in seconds,,i can only move the mouse and the pc starts beeping...
its aNNOYING! bootlogs dont show anything!like nothin unusual.
i disabled the soundcard in bios,but its not her...
i tried making new master boot records,fixboot,fixmbr,didnt help...
scaned half of my ram and hard for errors but none,they seem healthy.
now as a last ACT of desperation i unplugen the sata cable from the motherboard.the disk was set to SATA slot 1 i pluget it in SATA slot 3 and it loaded normal...so now i play the waiting game..i hope it was just bugged slot 1... i cant take this anymore >_< someone help if u can ):

and its not a virus,i tried all the antivirus,spyware,rootkits..clean

[edit on 10/11/08 by Unisol]

Have you run some kind of memory scanner on your computer?
And, have you tried running safemode?

safemoda works,i run a memory scan,0 errors..safemode wont fix anything,the windows crashes at random restarts...and its not from the software,ive tried windowses.and it was doing it as it came with instaled windows

reply to post by Unisol


Do you still have the windows disc? You may want to try running a repair, or maybe even reloading windows.