Parallel tools installation in Parallels 5 fails

Parallels 5 upgrade seems to have worked, but when I clicked to install what is apparently an upgrade to the Parallels tools, I repeatedly received an error NTVDM CPU has encountered an illegal instruction error in a box labeled 16 bit MS-Dos Subsystem. I have attached a selective screen shot made with Grab. I don't know what state the Parallels Tools upgrade is. I am using a Macbook Pro with OSX 10.5.8; this has a 2.2ghz Intel Core 2 Duo processor with 2GB of 667mhz ddr2 sdram. Thanks for your help.

 

Hi Joe,
please check Microsoft support article: http://support.microsoft.com/kb/314106
And, you can check this thread at the bottom of the page referring to AVG.