Since you had to do a Custom(clean) install, I would assume you have to reinstall Vista like you did when you first got it. If you activated and if Microsoft is correct, you may not be able to reactivate your Vista copy, it may take a phone call.
Are you running a 32 or 64 bit version of 7? Are you having hardware or software problems? Maybe we could work on those problems and keep you happy with 7, it does have quite a bit of software compatibility built in, and really should be more compatible than Vista.
Operating System Win 7 x64
Computer Type Homebuilt
OS Service Pack 2
DirectX Version 11
CPU Type and Speed i7 3770K
Motherboard Chipset Asus P8Z77-V Pro
System Memory Type 16 GB Kingston
Video Card Type and Speed Nvidia GTX 680 (2)
Computer Monitor LG 27" (3)
Hard Drive Kingston 240 SSD
Optical Drives LG WH12LS30 Blu-
Modem-Router Type Linksys E3000
Network Adapter Intel Gigabit
Anti-virus Software MSE
Computer Skill Level Average Ability
Windows Experience Index 7.7