First, you must be on an unrestricted account to install ans remove programs.
I would picture that Trend Micro would un-install by using start,all programs, trend micro, un-install.
Restart your computer.
Download and install AVG again, from here. Please disable and download accelerators. They seem to corrupt the download.
http://free.grisoft.com/doc/2/
If things don't work out, I suggest that you post a new discussing asking for help here. They have probably been through this, already.
http://forums.cnet.com/5204-6132_102-0.html?forumID=32
Rick
TrendMicro AntiVirus keeps blocking downloads such as GoogleEarth and even its own Trendmicro updates! A repair shop put this piece of junk on my laptop and I want it off. I went to Control Panel to Uninstall Programs. I ununstalled Trend Micro Antivirus, coldbooted my machine, then downloaed AVG Antivirus which would not install because AVG detected another antivirus program on my laptop, presumable remaining parts of the TrendMicro which were not really deleted.
I reluctantly reloaded TrendMicro Antivirus just so I would have some Antiviral protection. However, it is interfering with my ability to download things and and download its updated virus definitions...so I am reallyu not protected against viruses but I cannot use another antivirus program.
Interestingly, I CAN download updates to Microsoft programs and my AVG SPYWARE but not my Windows Defender.
I have an HP9400 series Vista maching with 2mg of memory before I use my 2mg jumpdrive to add memory.

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