Package Manager Freezes

Hi, all. I've just experienced a problem using Package Manager in TS2012. I've been downloading a lot of free- and pay ware from a bunch of sources and this is the first time I've had this happen. I usually start Steam alone before starting TS, just to check the latest news. I start TS, it seems to start normally. I go to the Package Manager tab and press "Refresh" as I always do and this seems OK. I press "Install" and it hangs up at this screen:
My list of file locations and folders in the left sidebar is incomplete and the TS window in the background shows "Not Responding". The only way I can get out of it is to ungracefully exit. This started yesterday. Here's what I've done up to now:
- restarted TS, no effect
- restarted Steam and TS, no effect
- verified cache several times, no effect
- ran Norton Antivirus full scan, nothing found, no effect
- ran scandisk, no effect
- ran defrag, no effect
- removed unnecessary files using CCleaner, no effect
- shut down and restarted the laptop, no effect
Has anyone experienced anything similar and found an answer? I'm getting really frustrated at this point!

All suggestions gratefully accepted.
Best,
Marc
My list of file locations and folders in the left sidebar is incomplete and the TS window in the background shows "Not Responding". The only way I can get out of it is to ungracefully exit. This started yesterday. Here's what I've done up to now:
- restarted TS, no effect
- restarted Steam and TS, no effect
- verified cache several times, no effect
- ran Norton Antivirus full scan, nothing found, no effect
- ran scandisk, no effect
- ran defrag, no effect
- removed unnecessary files using CCleaner, no effect
- shut down and restarted the laptop, no effect
Has anyone experienced anything similar and found an answer? I'm getting really frustrated at this point!


All suggestions gratefully accepted.
Best,
Marc