I will show u how to downgrade patches.
We have got v1.7 say and we wan't to go back to v1.6, here is how to do it. This is for windows xp only. That also means sp1 + profes etc.
1.Open the start menu and select run
2.Type regedit.exe and the regedit will open.
3.On the left side there should be 4 folders. U wan't HKEY_LOCAL_MACHINE then SOFTWARE then Activsion then call of duty 4. Now look on the right side.
4.Double click version and replace 1.7 with 1.5 click ok then close
the regedit.Now run the 1.6 to 1.7 patch and unstall it.
5.Now run the 1.6 patch and unstall that(don't give me backshat just follow my orders)
6.now run the 1.6 patch again to install it. There we go U have got 1.6 back.
This is the same with 1.6 downgrading to 1.5 or under.
Hope I helped
oh god thank you bro this works ur tha man!
To do this on vista u do the same. control and r open regedit.