Windows 7 MAJOR Problems getting W7 to run

[sainttomm]

Hi everyone!

I'm having some real issues getting Windows 7 to run on my computer. I managed to half solve one, but the torment continues and I haven't really got any idea why.

Background:
Clean install of W7 from download, followed by DVD, on a PC which was running XP Home perfectly:

• Intel Pentium D 3.40GHz
• Motherboard: MSI MS-7173, mATX, ATI RC410, PCIe, DDR2
• 1024Mb RAM
• nVidia GeForce 7300 GT
• 250Gb free HD, and separate 500Gb drive
• Windows 7 Professional Premium 32Bit, Build 7600

I ran the the Windows 7 Upgrade advisor before I bought it, and it only flagged my graphics card up as an issue, saying it would be unable to handle Aero effects. However I do not think this is the problem (see below)

Problems:

1. Immediately after clean install, Windows 7 would not load for the first time. Worked ok in safe mode, but normal start up would just freeze.
   • I solved this by disabling the service "Multimedia Class Scheduler" in the Startup menu in System Configuration, which was seemingly the cause of the problem, but am unsure what this service actually does
2. Now, my major problem is that when I open a program (e.g. Firefox, one of the very few things I have installed), it takes an age to load (in the region of 5 minutes), and if you interrupt it by trying to do anything else the whole system freezes and crashes. With other programs, e.g. the built in Calculator program, it doesn't run at all and just locks up the Taskbar and, eventually, the whole system.

Things that DO work:

1. Wireless connection (via Belkin USB adaptor)
2. Internet connection
3. Browsing files and folders using Explorer
4. Installed Firefox 3.5.3 using executable run from Explorer
5. All themes and visual effects

Things I have tried:

1. Updated drivers for Graphics card (from Nvidia site, W7 compatible) and Network adaptors
2. Physically removed all USB devices and even all PCI cards including Graphics card (I have therefore pretty much ruled this out as a cause of my woes, as the problems still occurred when nothing was attached but a mouse, keyboard and monitor via the motherboard)
3. Installing W7 as a clean install from the download over windows XP, cleanly on its own and as a dual boot on a separate partition, using both the download and a bootable DVD made from an iso of the downloaded files
4. Disabling all but the basic System Services
5. Disabling all visual effects in Performance options under System Properties (and increasing virtual memory)
6. Running Windows Update to get any newly released updates from Microsoft
7. Changed theme from Aero to Basic
8. Probably some other other things I've tried but haven't remembered to put down here...

PLEASE HELP!!!
I am actually going mad - have been mucking around with this for 2 days now. I'm starting to think I wasted my money and should get a refund and go back to XP... please prove me wrong!