This question seems to pop up in waves in these forums.
If you can't even get to the menus, then temporarily disconnect from the Internet (pull out the cable), then launch Photoshop and set your online preferences to NEVER check for updates. After that you can reconnect to the Internet.
Your problem will be gone forever.
If you are using Photoshop 7: The last update for Photoshop 7.x was 7.0.1. Make sure you have applied that update. After that, there will not be any updates for 7.x, so you'll miss nothing by having your online preferences set to NEVER check for updates.
If you are using Photoshop CS ( a.k.a 8 ): Photoshop CS is set to NEVER check for updates by default.
You can always navigate to Adobe.com and check for their product updates you may wish to download and install.
[Thanks to Ramón G Castañeda for the above solution]