Start up takes about 10 mins

Start up takes about 10-15 mins and everything seems very slugish and now internet doesn't work it says something like unrecognized server,i have 5 operating systems on my pc and all the others are fine,which is how i'm able to type this,lol.Its just my main vista 64 ultimate that is messed up.I have defragmented and checked for errors but its still this same,in fact thats when the net went down.

Intel® Core™2 Quad Extreme QX9650 Processor (3.0GHz, 12MB Cache, 1333MHz)
Vista Ultimate Edition 64 bit main O/S
XP32 bit,vista ultimate 32/64 bit quintuple boot
Coolermaster Cosmos S Ultra Performance Aluminium Chassis with 1250W PSU
Cooling Pack for COSMOS S Chassis ( 5 LED 120mm fans)
Performance Pack - OCZ Vendetta Heat pipe quiet cooling
PCI-Express Mainboard - SLi nForce 780i SLi - Intel Core2Duo/Quad Core - ATX
8GB DDR2 800MHz Memory (4 x 2GB)
2 x 1000GB Serial ATA 2 Hard Drive with 32MB Buffer (2TB Total)
Blu-ray ROM Player Dual layer DVD Writer 24 x CD Writer
Super Format 20x Dual Layer DVD Writer +R/-R/RW/RAM
2x GTX260(swappped over from 2x 9800GX2)
28" Widescreen LCD TFT Digital Display with internal speakers (DVI, 3ms)
Creative Labs Sound Blaster X-Fi Xtreme Gamer Sound Card

why don't you try a system restore first?

have you scanned for viruses an spywares?

Gothnezz suggestion is good. Use your AntiVirus to make a full Virus Scan. Then use this to check for malware. Malwarebytes.org


In addition, turn off your anti virus and see if that speeds things up.

You can also try a clean boot and see how it goes.
http://support.microsoft.com/kb/929135

Good Luck