Never had any troubles with version3. However -- version4 is total failure here. Evaluation edition installs nicely, updates smoothly. Restart -- BSOD - Stop Error 1E I'm speaking about 64bit version as I use Windows XP 64bit SP2 with all the latest updates. Nothing really unusual about my system, Nforce + GForce drivers (intel c2d CPU). Apart from that, pretty much nothing special. Tried several times, result is 100% same. Every time had to uninstall v4 in Safe mode. After that, all business as usual. BTW, another fail -- in safe mode, the installation offers to "repair" it as well, which is not possible as NOD32 cannot be started.....
Do you have Nvidia firewall installed by chance? Please check if "Network access manager" appears in "Control panel > Add/remove programs".