Computer got slower after a reinstall of Windows

[yakahughes]

I just reinstalled Windows on my Toshiba A505-S6035 and since the reinstall, the computer got pretty slow, apparently mainly on disk access. I installed all the relevant drivers from the Toshiba page, so I don't think that's the problem. Here's the specs:

Windows 7 Professional x64
4 GB DDR3 ram
Intel Core i7 720QM
500 GB Hitachi HDD

Any reason anybody can think of that would have slowed it down rather than speeding it up?

[Murk]

Perhaps it's indexing all the files. Check if SearchIndexer.exe is active.