Spybot Deleted!!!

[bigo72]

Hi everybody,
some time more and I'll be completely mad: I'm sure that I have a malware in my system, everything is slow and every kind of malware detector not works.
I can't install Spybot, because it is deleted after installation.
I tryed ClamWin Portable, from an usb storage pendrive, and it's deleted.
My F8 key at boot reboot PC without enter in safe-mode.
Just Ad-Aware works, but don't find nothing important (just some tracking cookies).

What can I do?

Please help me: I need one week to format and re-install, 'cause all my work is on my PC, I need to remove this "animal" from my PC....absolutely.

Thanks

[md usa spybot fan]

Consider posting in the Malware Removal (http://forums.spybot.info/forumdisplay.php?f=22) forum and having someone take a look at your system. Follow the instructions here:
"BEFORE you POST" Mandatory Steps Before Requesting Assistance.
http://forums.spybot.info/showthread.php?t=288
After completing those steps, start a new thread (topic) in the following forum (making sure to include the HijackThis log and online scan logs produced from the instructions above):
Malware Removal
http://forums.spybot.info/forumdisplay.php?f=22
Note: Although you can’t run a Spybot scan, make sure that you run an online anti-virus scan and post the results along with the HijackThis log.