Let talk about the story that my windows XP got this problem:
i download a crack from a website,then i double click the exe file.
tha file installed...but my microsoft antispyware detect the virus..so i click remove the virus...it seen got many trojan viruses..
after complete remove the viruses...this antispyware ask me to restart my windows..
OK,i restart...SUCK..
after restart..my desktop screen becomes black color..
and it auto reboot n reboot evertime windows start.
i turn in safe mode and notice in my hard disk got 2 weird program..
i delete it..1. drsmartload46a-this icon look like a utility icon
2. WinFrgn setup icon
then i use my WinXP CD n boot in in DOS..repair my windows...
the error code=0x8007007f occur while windows completing installation.
i ignore it.
after installation complete.windows start...
but the blue windows starting screen load very slow...before is <10s
the windows can start, but i cannot change my desktop..it always load the black color skin with(NONE). some times the blue screen with: DUMP MEMORY come after windows start a while...n i need to restart it again.
My antispyware, hijackthis software cannot run.
i browse the web.some web page only display as blank page.
I really don;t know how to solve it...
i don't want to install a new WinXP.because this will format my hardisk.

Can Somebody give me some guidesss!

Disconnect your computer from the internet, boot to safemode. clear all the items in the startup.
start->run->type msconfig and hit enter.
Click on the startup tab in teh system configuration utility. Uncheck all the items on in the list except for anti-virus , firewall.
Uninstall all the dirty programs you remember you installed from "Add remove program".
Create a new user account from the control panel, now restart the computer and login to the new account. See how the computer behaves.