2 of your minidumps were generic and they don't tell us much.
4 of your minidumps all point to ALCXSENS.sys which is a Sensaura WDM 3D Audio Driver belongs to the software Service for WDM 3D Audio Driver by Sensaura Ltd.
Certain other drivers were cited in these 4 minidumps as well. The two in particular were gta-vc.exe and BF1942. The former belongs to Vice City which has a patch out and the latter to Battlefiled 1942.
1 minidump is an 0x8E citing Pool_Corruption which means you have bad drivers corrupting your driver pool. In this error hpqtra08.exe is noted which is an Hewlett-Packard Digital driver.
Now we come to the most interesting one: cdnprot.sys and everything I have read it is a nasty backdoor trojan. You are infected.
Here are my suggestions:
1. Be very careful where you suf on the internet and what you download/view.
2. If you haven't already you need to sit behind a router, a good anti-virus, antispyware, and a firewall. But even the best security can'r protect us fully without good web surfing habits.
3. Are you running XP with all service packs? If not you need to pronto but not until you do step 4 first.
4. As soon as possible run virus scan, malware scan, rootkit scan BUT before doing so check out the Security and the Web forum here and read the stickies at the top.
5. Once cleaned out see how your system runs. You probably will need to update all your drivers as well.